Obstetrics

NATIONAL HARBOR, MARYLAND — Women who experience an adverse pregnancy outcome during their first pregnancy are significantly more likely to experience either the same or any adverse pregnancy outcome in a subsequent pregnancy than are those with no adverse pregnancy outcome during a first pregnancy, based on data from more than 4000 individuals.

Adverse pregnancy outcomes (APOs) occur in approximately 20%-30% of pregnancies and contribute to significant perinatal morbidity, William A. Grobman, MD, of The Ohio State University, Columbus, said in a presentation at the Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine (abstract 17).

Risk factors for APOs include nulliparity and prior APOs, as well as age, body mass index, and blood pressure, he said. However, less is known about factors identified early in a first pregnancy that might predict an APO in a second pregnancy, he explained.

Dr. Grobman and colleagues used data from the nuMoM2b Heart Health Study, a cohort of more than 10,000 nulliparous women at eight sites in the United States.

The current study included a subset of individuals with two pregnancies of at least 20 weeks’ gestation who were followed for up to 7 years after delivery via telephone and in-person visits and for whom APO information was available.

An APO was defined as any of a range of outcomes including hypertensive disorders of pregnancy, preterm birth at less than 37 weeks’ gestation, small-for-gestational age at birth (less than 5th percentile for weight), gestational diabetes, or fetal death.

The goal of the study was to determine patterns of APOs across two pregnancies, and to identify factors in the first pregnancy that might be associated with these patterns, Dr. Grobman said.

The study population included 4253 women from the nuMOM2b; of these, 1332 (31%) experienced an APO during their first pregnancies.

Women with an APO during the first pregnancy were significantly more likely to have a second APO than were those with no initial APO (40% vs. 15%), said Dr. Grobman. Overall, the APO that occurred most frequently in the first pregnancy was the one most likely to occur in the second.

However, “the increased risk for an APO during a second pregnancy was greater for any APO in women with a history of any APO compared to women with no prior APO,” he said.

In this study, the most common APOs were gestational diabetes and hypertensive disorders of pregnancy.

“In general, no risk markers were associated with a particular pattern of APO development,” Dr. Grobman said.

However, some markers from the first trimester of the first pregnancy were significantly associated with an APO in the second pregnancy, including body mass index, age older than 35 years, blood pressure, and cardiometabolic serum analytes. Also, the magnitude of APO recurrence risk was highest among non-Hispanic Black individuals compared with other ethnicities.

The findings were limited by a lack of data on placental pathology, Dr. Grobman noted during the discussion. However, the findings underscored the need to better understand the risk factors for APOs and develop prevention strategies, he said. The results also emphasize the need to account for transitions of care for patients who experience an APO, he added.
 

Data May Inform Patient Guidance

“Patients with an adverse pregnancy outcome in a first pregnancy often experience considerable anxiety when thinking about a second pregnancy,” Joseph R. Biggio Jr., MD, a maternal-fetal medicine specialist at Ochsner Health in New Orleans, said in an interview.

“This study helps to provide insight into factors which may be associated with increased risk in a subsequent pregnancy, and importantly identifies some factors that are potentially modifiable, such as BMI and blood pressure,” said Dr. Biggio, who served as a moderator for the session in which the study was presented.

“Based on the findings from this analysis, we need research to determine whether these findings apply to not only patients having their first pregnancy, but also adverse outcomes in any pregnancy,” Dr. Biggio said in an interview. “In addition, we need to explore whether modification of any of these risk factors can improve pregnancy outcomes, so that all patients can have the birth experience that they desire,” he said.

The study received no outside funding. Dr. Grobman and Dr. Biggio had no financial conflicts to disclose.

NATIONAL HARBOR, MARYLAND — Women who experience an adverse pregnancy outcome during their first pregnancy are significantly more likely to experience either the same or any adverse pregnancy outcome in a subsequent pregnancy than are those with no adverse pregnancy outcome during a first pregnancy, based on data from more than 4000 individuals.

Adverse pregnancy outcomes (APOs) occur in approximately 20%-30% of pregnancies and contribute to significant perinatal morbidity, William A. Grobman, MD, of The Ohio State University, Columbus, said in a presentation at the Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine (abstract 17).

Risk factors for APOs include nulliparity and prior APOs, as well as age, body mass index, and blood pressure, he said. However, less is known about factors identified early in a first pregnancy that might predict an APO in a second pregnancy, he explained.

Dr. Grobman and colleagues used data from the nuMoM2b Heart Health Study, a cohort of more than 10,000 nulliparous women at eight sites in the United States.

The current study included a subset of individuals with two pregnancies of at least 20 weeks’ gestation who were followed for up to 7 years after delivery via telephone and in-person visits and for whom APO information was available.

An APO was defined as any of a range of outcomes including hypertensive disorders of pregnancy, preterm birth at less than 37 weeks’ gestation, small-for-gestational age at birth (less than 5th percentile for weight), gestational diabetes, or fetal death.

The goal of the study was to determine patterns of APOs across two pregnancies, and to identify factors in the first pregnancy that might be associated with these patterns, Dr. Grobman said.

The study population included 4253 women from the nuMOM2b; of these, 1332 (31%) experienced an APO during their first pregnancies.

Women with an APO during the first pregnancy were significantly more likely to have a second APO than were those with no initial APO (40% vs. 15%), said Dr. Grobman. Overall, the APO that occurred most frequently in the first pregnancy was the one most likely to occur in the second.

However, “the increased risk for an APO during a second pregnancy was greater for any APO in women with a history of any APO compared to women with no prior APO,” he said.

In this study, the most common APOs were gestational diabetes and hypertensive disorders of pregnancy.

“In general, no risk markers were associated with a particular pattern of APO development,” Dr. Grobman said.

However, some markers from the first trimester of the first pregnancy were significantly associated with an APO in the second pregnancy, including body mass index, age older than 35 years, blood pressure, and cardiometabolic serum analytes. Also, the magnitude of APO recurrence risk was highest among non-Hispanic Black individuals compared with other ethnicities.

The findings were limited by a lack of data on placental pathology, Dr. Grobman noted during the discussion. However, the findings underscored the need to better understand the risk factors for APOs and develop prevention strategies, he said. The results also emphasize the need to account for transitions of care for patients who experience an APO, he added.
 

Data May Inform Patient Guidance

“Patients with an adverse pregnancy outcome in a first pregnancy often experience considerable anxiety when thinking about a second pregnancy,” Joseph R. Biggio Jr., MD, a maternal-fetal medicine specialist at Ochsner Health in New Orleans, said in an interview.

“This study helps to provide insight into factors which may be associated with increased risk in a subsequent pregnancy, and importantly identifies some factors that are potentially modifiable, such as BMI and blood pressure,” said Dr. Biggio, who served as a moderator for the session in which the study was presented.

“Based on the findings from this analysis, we need research to determine whether these findings apply to not only patients having their first pregnancy, but also adverse outcomes in any pregnancy,” Dr. Biggio said in an interview. “In addition, we need to explore whether modification of any of these risk factors can improve pregnancy outcomes, so that all patients can have the birth experience that they desire,” he said.

The study received no outside funding. Dr. Grobman and Dr. Biggio had no financial conflicts to disclose.

NATIONAL HARBOR, MARYLAND — Women who experience an adverse pregnancy outcome during their first pregnancy are significantly more likely to experience either the same or any adverse pregnancy outcome in a subsequent pregnancy than are those with no adverse pregnancy outcome during a first pregnancy, based on data from more than 4000 individuals.

Adverse pregnancy outcomes (APOs) occur in approximately 20%-30% of pregnancies and contribute to significant perinatal morbidity, William A. Grobman, MD, of The Ohio State University, Columbus, said in a presentation at the Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine (abstract 17).

Risk factors for APOs include nulliparity and prior APOs, as well as age, body mass index, and blood pressure, he said. However, less is known about factors identified early in a first pregnancy that might predict an APO in a second pregnancy, he explained.

Dr. Grobman and colleagues used data from the nuMoM2b Heart Health Study, a cohort of more than 10,000 nulliparous women at eight sites in the United States.

The current study included a subset of individuals with two pregnancies of at least 20 weeks’ gestation who were followed for up to 7 years after delivery via telephone and in-person visits and for whom APO information was available.

An APO was defined as any of a range of outcomes including hypertensive disorders of pregnancy, preterm birth at less than 37 weeks’ gestation, small-for-gestational age at birth (less than 5th percentile for weight), gestational diabetes, or fetal death.

The goal of the study was to determine patterns of APOs across two pregnancies, and to identify factors in the first pregnancy that might be associated with these patterns, Dr. Grobman said.

The study population included 4253 women from the nuMOM2b; of these, 1332 (31%) experienced an APO during their first pregnancies.

Women with an APO during the first pregnancy were significantly more likely to have a second APO than were those with no initial APO (40% vs. 15%), said Dr. Grobman. Overall, the APO that occurred most frequently in the first pregnancy was the one most likely to occur in the second.

However, “the increased risk for an APO during a second pregnancy was greater for any APO in women with a history of any APO compared to women with no prior APO,” he said.

In this study, the most common APOs were gestational diabetes and hypertensive disorders of pregnancy.

“In general, no risk markers were associated with a particular pattern of APO development,” Dr. Grobman said.

However, some markers from the first trimester of the first pregnancy were significantly associated with an APO in the second pregnancy, including body mass index, age older than 35 years, blood pressure, and cardiometabolic serum analytes. Also, the magnitude of APO recurrence risk was highest among non-Hispanic Black individuals compared with other ethnicities.

The findings were limited by a lack of data on placental pathology, Dr. Grobman noted during the discussion. However, the findings underscored the need to better understand the risk factors for APOs and develop prevention strategies, he said. The results also emphasize the need to account for transitions of care for patients who experience an APO, he added.
 

Data May Inform Patient Guidance

“Patients with an adverse pregnancy outcome in a first pregnancy often experience considerable anxiety when thinking about a second pregnancy,” Joseph R. Biggio Jr., MD, a maternal-fetal medicine specialist at Ochsner Health in New Orleans, said in an interview.

“This study helps to provide insight into factors which may be associated with increased risk in a subsequent pregnancy, and importantly identifies some factors that are potentially modifiable, such as BMI and blood pressure,” said Dr. Biggio, who served as a moderator for the session in which the study was presented.

“Based on the findings from this analysis, we need research to determine whether these findings apply to not only patients having their first pregnancy, but also adverse outcomes in any pregnancy,” Dr. Biggio said in an interview. “In addition, we need to explore whether modification of any of these risk factors can improve pregnancy outcomes, so that all patients can have the birth experience that they desire,” he said.

The study received no outside funding. Dr. Grobman and Dr. Biggio had no financial conflicts to disclose.

WASHINGTON — Continuous glucose monitoring (CGM) is widely used during pregnancy for individuals with type 1 diabetes — with pregnancy-specific target metrics now chosen and benefits on perinatal outcomes demonstrated — but more research is needed to elucidate its role in the growing population of pregnant people with type 2 diabetes and gestational diabetes (GDM). And overall, there are still “many more questions unanswered about CGM use in pregnancy than what we have answered,” Celeste Durnwald, MD, said at the biennial meeting of the Diabetes in Pregnancy Study Group of North America.

There’s much to learn about how to best interpret “the detailed and complex data that CGM provides,” and what targets in addition to time in range (TIR) are most important, said Dr. Durnwald, director of the perinatal diabetes program and associate professor of ob.gyn. at the Hospital of the University of Pennsylvania, Philadelphia, in a presentation on CGM.

Among other questions are whether fasting glucose is “as important in the era of CGM,” and whether there should be different glycemic targets for nocturnal versus daytime TIR, she said. Moreover, questions justifiably remain about whether the TIR targets for type 1 diabetes in pregnancy are indeed optimal, she said in a discussion period.

Ongoing research is looking at whether CGM can motivate and guide patients with GDM through diet and lifestyle changes such that “we can see changes in amounts of medication we use,” Dr. Durnwald noted in her presentation. “There’s a whole breadth of research looking at whether CGM can help predict diagnosis of GDM, large for gestational age, or preeclampsia, and what are the targets.”

Maternal hypoglycemia during pregnancy — a time when strict glycemic control is recommended to reduce the risk of congenital malformations and other fetal and neonatal morbidity — remains a concern in type 1 diabetes, even with widespread use of CGM in this population, said Barak Rosenn, MD, during a presentation on glycemic control in type 1 diabetes.

A pilot study of a newly designed pregnancy-specific closed-loop insulin delivery system, published last year (Diabetes Care. 2023;46:1425-31), has offered the first “really encouraging information about the ability to use our most up-to-date technology to help our type 1 patients maintain strict control and at the same time decrease their risk of severe hypoglycemia,” said Dr. Rosenn, a maternal-fetal medicine specialist at the Jersey City Medical Center, Jersey City, New Jersey.

Guidance for tight intrapartum glucose control, meanwhile, has been backed by little evidence, said Michal Fishel Bartal, MD, MS, and some recent studies and reviews have shown little to no effect of such tight control on neonatal hypoglycemia, which is the aim of the guidance.

“We need to reexamine current recommendations,” said Dr. Bartal, assistant professor in the division of maternal-fetal medicine at the University of Texas Health Science Center, Houston, during a presentation on intrapartum care. “There’s very limited evidence-based data for the way we manage people with diabetes [during labor and delivery].”

The Knowns And Unknowns of CGM in Pregnancy

The multicenter, international CONCEPTT trial (Continuous Glucose Monitoring in Pregnant Women With Type 1 Diabetes), published in 2017, was the first trial to demonstrate improvements in perinatal outcomes, and it “brought CGM to the forefront in terms of widespread use,” Dr. Durnwald said.

The trial randomized more than 300 patients with type 1 diabetes who were pregnant or planning pregnancy (both users of insulin pumps and users of multiple insulin injections) to continuous, real-time CGM in addition to finger-stick glucose monitoring, or standard finger-stick glucose tests alone. In addition to small improvements in A1c and 7% more TIR (without an increase in hypoglycemia), pregnant CGM users had reductions in large-for-gestational age (LGA) births (53% vs 69%, P = .0489), neonatal intensive care admissions lasting more than 24 hours, and severe neonatal hypoglycemia.

Numbers needed to treat to prevent adverse outcomes in the CONCEPTT trial were six for LGA, six for NICU admission, and eight for neonatal hypoglycemia.

Data from the CONCEPTT trial featured prominently in the development of consensus recommendations for CGM targets in pregnancy by an international expert panel endorsed by the American Diabetes Association. In its 2019 report, the group recommended a target range of 63-140 mg/dL for type 1 and type 2 diabetes during pregnancy (compared with 70-180 mg/dL outside of pregnancy), and a TIR > 70% for pregnant people with type 1 diabetes. (Targets for time below range and time above range are also defined for type 1.)

More data are needed, the group said, in order to recommend TIR targets for type 2 diabetes in pregnancy or GDM (Diabetes Care. 2019;42:1593-603). “Many argue,” Dr. Durnwald said, “that there could be more stringent targets for those at less risk for [maternal] hypoglycemia, especially our GDM population.”

There’s a question of whether even higher TIR would further improve perinatal outcomes, she said, “or will we reach a threshold where higher TIR doesn’t get us a [further] reduction in LGA or preeclampsia.”

And while TIR is “certainly our buzzword,” lower mean glucose levels have also been associated with a lower risk of LGA and other adverse neonatal outcomes. A 2019 retrospective study from Sweden, for instance, analyzed patterns of CGM data from 186 pregnant women with type 1 diabetes and found significant associations between elevated mean glucose levels (in the second and third trimesters) and both LGA and an adverse neonatal composite outcome (Diabetologia. 2019;62:1143-53).

Elevated TIR was also associated with LGA, but “mean glucose had the strongest association with the rate of LGA,” Dr. Durnwald said.

Similarly, a 2020 subanalysis of the CONCEPTT trial data found that a higher mean glucose at both 24 and 34 weeks of gestation was significantly associated with a greater risk of LGA (Diabetes Care. 2020;43:1178-84), and a smaller 2015 analysis of data from two randomized controlled trials of CGM in pregnant women with type 1 and type 2 diabetes found this association in trimesters 2 and 3 (Diabetes Care. 2015;38;1319-25).

The ADA’s Standards of Care in Diabetes (Diabetes Care. 2024;47:S282-S294) endorse CGM as an adjunctive tool in pregnancy — not as a replacement for all traditional blood glucose monitoring — and advise that the use of CGM-reported mean glucose is superior to the use of estimated A1c, glucose management indicator, and other calculations to estimate A1c. Changes occur in pregnancy, Dr. Durnwald pointed out. “Most experts will identify a [target] mean glucose < 120 mg/dL in those with type 1, but there’s potential to have a mean glucose closer to 100 in certainly our patients with GDM and some of our patients with type 2,” she said. To a lesser extent, researchers have also looked at the effect of CMG-reported glycemic variability on outcomes such as LGA, with at least two studies finding some association, and there has been some research on nocturnal glucose and LGA, Dr. Durnwald said. CGM “gives us the opportunity,” she said, “to think about nocturnal glucose as a possible target” for further optimizing diabetes management during pregnancy.

CGM in Type 2, GDM

CGM in type 2 diabetes in pregnancy was addressed in a recently published systematic review and meta-analysis, which found only three qualifying randomized controlled trials and concluded that CGM use was not associated with improvements in perinatal outcomes, as assessed by LGA and preeclampsia (Am J Obstet Gynecol MFM. 2023;5:100969). “It’s very limited by the small sample size and the fact that most [patients] were using intermittent CGM,” Dr. Durnwald said. “It highlights how important it is to perform larger studies with continuous CGM.”

While the 2024 ADA standards say there are insufficient data to support the use of CGM in all patients with type 2 diabetes or GDM — and that the decision should be individualized “based on treatment regimen, circumstance, preferences, and needs” — real-world access to CGM for type 2, and even a bit for GDM, is improving, she said.

Some insurers require patients to be on insulin, but the trends are such that “we certainly talk about CGM to all our patients with type 2 diabetes and even our patients with GDM,” Dr. Durnwald said in a later interview. “CGMs are being advertised so we definitely have people who ask about them upon diagnosis, and we try to make it work for them.”
 

Is Preventing Maternal Hypoglycemia Possible?

Advancements in technology and pharmacology aimed at optimizing glycemic control — increased adoption of CGM, the use of insulin pump therapy, and the use of more rapid insulin analogs — appear to have had little to no impact on rates of severe maternal hypoglycemia in type 1 diabetes in pregnancy, said Dr. Rosenn, referring to several published studies.

The CONCEPTT study in type 1 diabetes, for instance, “gave us the best data we have on the use of CGM,” but differences in the percentage of patients with severe hypoglycemia and the total number of severe hypoglycemia episodes were basically the same whether patients used CGM or not, he said.

Closed-loop insulin delivery systems have been found in nonpregnant patients with type 1 diabetes to “be helpful in keeping people in range and also possibly [decreasing nocturnal hypoglycemia],” but the systems are not approved for use in pregnancy. “There’s not enough data on use in pregnancy, but probably more important, the algorithms used in the closed-loop systems are not directed to the targets we consider ideal for pregnancy,” Dr. Rosenn said.

In a pilot study of a closed-loop delivery system customized for pregnancies complicated by type 1 diabetes, 10 pregnant women were recruited at 14-32 weeks and, after a 1- to 2-week run-in period using a regular CGM-augmented pump, they used the closed-loop system targeting a daytime glucose of 80-110 mg/dL and nocturnal glucose of 80-100 mg/dL.

Mean TIR (a target range of 63-140 mg/dL) increased from 65% during the run-in period to 79% on the closed-loop system, and there were significant decreases in both time above range and time in the hypoglycemic ranges of < 63 mg/dL and < 54 mg/dL. Hypoglycemic events per week (defined as < 54 mg/dL for over 15 minutes) decreased from 4 to 0.7 (Diabetes Care. 2023;46:1425-31).

The investigators are continuing their research, and there are currently two randomized controlled trials underway examining use of closed-loop systems designed for pregnancy, said Dr. Rosenn, who was involved in feasibility research leading up to the pilot study. “So I’m hopeful we’ll see some encouraging information in the future.”

Maternal hypoglycemia during pregnancy is more common in type 1 diabetes, but it also affects pregnancies complicated by type 2 diabetes and GDM. In addition to the strict glycemic control imposed to improve maternal and fetal outcomes, pregnancy itself plays a role.

Research several decades ago from the Diabetes in Pregnancy Program Project, a prospective cohort in Cincinnati which Dr. Rosenn co-led, documented impaired counterregulatory physiology in pregnancy. Even in nondiabetic patients, there are declines in secretion of glucagon and growth hormone in response to hypoglycemia, for instance. In patients with type 1 diabetes, the diminishment in counterregulatory response is more severe.

Rethinking Intrapartum Care

Guidance for tight blood glucose control during labor and delivery for insulin-treated individuals — as reflected in the American College of Obstetricians and Gynecologists Practice Bulletin No. 201 on Pregestational Diabetes and in recommendations from the United Kingdom’s National Institute for Health and Care Excellence (NICE) — is based on small case series and overall “poor-quality” evidence that more recent research has failed to back up, Dr. Bartal said.

A systematic review published in 2018, for example, concluded there is a paucity of high-quality data supporting the association of glucose during labor and delivery with neonatal hypoglycemia in pregnancies complicated by diabetes (Diabet Med. 2018;35:173-83). And in a subsequent retrospective cohort study of pregnant women with type 1/type 2/GDM and their neonates, the same investigators reported no difference in the target glucose in labor between those with and without neonatal hypotension, after adjustment for important neonatal factors such as LGA and preterm delivery (Diabet Med. 2020;37:138-46).

Also exemplifying the body of research, Dr. Bartal said, is another single-center retrospective study published in 2020 that evaluated outcomes in the years before and after the institution of a formal intrapartum insulin regimen (a standardized protocol for titration of insulin and glucose infusions) for women with pregestational or gestational diabetes. The protocol was associated with improved maternal glucose control, but an increased frequency of neonatal hypoglycemia (Obstet Gynecol. 2020;136:411-6).

Her own group at the University of Texas in Houston looked retrospectively at 233 insulin-treated pregnancies complicated by type 2 diabetes and found no significant difference in the rate of neonatal hypoglycemia between those placed on a drip and those who were not, Dr. Bartal said. Over 40% of the newborns had hypoglycemia; it occurred irrespective of the route of delivery as well (J Matern Fetal Neonatal Med. 2022;35:7445-51).

Only two published randomized controlled trials have evaluated blood sugar control in labor, she said. The first, published in 2006, compared a continuous insulin drip with a rotation of glucose and non–glucose-containing fluids in insulin-requiring diabetes and found no differences in maternal blood glucose (the primary outcome) and a similar risk of neonatal hypoglycemia (Am J Obstet Gynecol. 2006;195;1095-9).

The second RCT, published in 2019, evaluated tight versus liberalized control (60-100 mg/dL, checking every hour, versus 60-120 mg/dL, checking every 4 hours) in laboring women with GDM. The first neonatal blood glucose level was similar in both groups, while the mean neonatal blood glucose level in the first 24 hours of life was lower with tight control (54 vs 58 mg/dL, P = .49) (Obstet Gynecol. 2019;133:1171-7). Findings from a new RCT conducted at the University of Texas in Houston of usual care versus more permissive glucose control will be presented at the SMFM Pregnancy Meeting in February 2024, she said.

Neonatal hypoglycemia is associated with increased risk of NICU admission, “but it’s also associated with possible long-term developmental deficit,” Dr. Bartal said, with the risk highest in children exposed to severe, recurrent, or clinically undetected hypoglycemia. Research has documented significantly increased risks of low executive function and visual motor function, for instance, in children who experienced neonatal hypoglycemia.

The risk of neonatal hypoglycemia has been linked to a variety of factors outside of the intrapartum period such as diabetes control and weight gain during pregnancy, neonatal birth weight/LGA, neonatal adiposity, gestational age at delivery, maternal body mass index, smoking, and diabetes control prior to pregnancy, Dr. Bartal noted. Also challenging is the reality that neonatal hypoglycemia as a research outcome is not standardized; definitions have varied across studies.

Tight intrapartum control comes with “costs,” from close monitoring of labor to increased resource utilization, and it may affect the labor experience/satisfaction, Dr. Bartal said. “But furthermore,” she said, “there are studies coming out, especially in the anesthesiology journals, that show there may be possible harm,” such as the risk of maternal and neonatal hyponatremia, and maternal hypoglycemia. A 2016 editorial in Anaesthesia (2016;71:750) describes these concerns, she noted.

“I do think we need to rethink our current recommendations,” she said.

Dr. Durnwald reported serving on the Dexcom GDM advisory board and receiving funding from United Health Group and the Helmsley Charitable Trust. Dr. Bartal and Dr. Rosenn reported no conflicts of interest.

WASHINGTON — Continuous glucose monitoring (CGM) is widely used during pregnancy for individuals with type 1 diabetes — with pregnancy-specific target metrics now chosen and benefits on perinatal outcomes demonstrated — but more research is needed to elucidate its role in the growing population of pregnant people with type 2 diabetes and gestational diabetes (GDM). And overall, there are still “many more questions unanswered about CGM use in pregnancy than what we have answered,” Celeste Durnwald, MD, said at the biennial meeting of the Diabetes in Pregnancy Study Group of North America.

There’s much to learn about how to best interpret “the detailed and complex data that CGM provides,” and what targets in addition to time in range (TIR) are most important, said Dr. Durnwald, director of the perinatal diabetes program and associate professor of ob.gyn. at the Hospital of the University of Pennsylvania, Philadelphia, in a presentation on CGM.

Among other questions are whether fasting glucose is “as important in the era of CGM,” and whether there should be different glycemic targets for nocturnal versus daytime TIR, she said. Moreover, questions justifiably remain about whether the TIR targets for type 1 diabetes in pregnancy are indeed optimal, she said in a discussion period.

Ongoing research is looking at whether CGM can motivate and guide patients with GDM through diet and lifestyle changes such that “we can see changes in amounts of medication we use,” Dr. Durnwald noted in her presentation. “There’s a whole breadth of research looking at whether CGM can help predict diagnosis of GDM, large for gestational age, or preeclampsia, and what are the targets.”

Maternal hypoglycemia during pregnancy — a time when strict glycemic control is recommended to reduce the risk of congenital malformations and other fetal and neonatal morbidity — remains a concern in type 1 diabetes, even with widespread use of CGM in this population, said Barak Rosenn, MD, during a presentation on glycemic control in type 1 diabetes.

A pilot study of a newly designed pregnancy-specific closed-loop insulin delivery system, published last year (Diabetes Care. 2023;46:1425-31), has offered the first “really encouraging information about the ability to use our most up-to-date technology to help our type 1 patients maintain strict control and at the same time decrease their risk of severe hypoglycemia,” said Dr. Rosenn, a maternal-fetal medicine specialist at the Jersey City Medical Center, Jersey City, New Jersey.

Guidance for tight intrapartum glucose control, meanwhile, has been backed by little evidence, said Michal Fishel Bartal, MD, MS, and some recent studies and reviews have shown little to no effect of such tight control on neonatal hypoglycemia, which is the aim of the guidance.

“We need to reexamine current recommendations,” said Dr. Bartal, assistant professor in the division of maternal-fetal medicine at the University of Texas Health Science Center, Houston, during a presentation on intrapartum care. “There’s very limited evidence-based data for the way we manage people with diabetes [during labor and delivery].”

The Knowns And Unknowns of CGM in Pregnancy

The multicenter, international CONCEPTT trial (Continuous Glucose Monitoring in Pregnant Women With Type 1 Diabetes), published in 2017, was the first trial to demonstrate improvements in perinatal outcomes, and it “brought CGM to the forefront in terms of widespread use,” Dr. Durnwald said.

The trial randomized more than 300 patients with type 1 diabetes who were pregnant or planning pregnancy (both users of insulin pumps and users of multiple insulin injections) to continuous, real-time CGM in addition to finger-stick glucose monitoring, or standard finger-stick glucose tests alone. In addition to small improvements in A1c and 7% more TIR (without an increase in hypoglycemia), pregnant CGM users had reductions in large-for-gestational age (LGA) births (53% vs 69%, P = .0489), neonatal intensive care admissions lasting more than 24 hours, and severe neonatal hypoglycemia.

Numbers needed to treat to prevent adverse outcomes in the CONCEPTT trial were six for LGA, six for NICU admission, and eight for neonatal hypoglycemia.

Data from the CONCEPTT trial featured prominently in the development of consensus recommendations for CGM targets in pregnancy by an international expert panel endorsed by the American Diabetes Association. In its 2019 report, the group recommended a target range of 63-140 mg/dL for type 1 and type 2 diabetes during pregnancy (compared with 70-180 mg/dL outside of pregnancy), and a TIR > 70% for pregnant people with type 1 diabetes. (Targets for time below range and time above range are also defined for type 1.)

More data are needed, the group said, in order to recommend TIR targets for type 2 diabetes in pregnancy or GDM (Diabetes Care. 2019;42:1593-603). “Many argue,” Dr. Durnwald said, “that there could be more stringent targets for those at less risk for [maternal] hypoglycemia, especially our GDM population.”

There’s a question of whether even higher TIR would further improve perinatal outcomes, she said, “or will we reach a threshold where higher TIR doesn’t get us a [further] reduction in LGA or preeclampsia.”

And while TIR is “certainly our buzzword,” lower mean glucose levels have also been associated with a lower risk of LGA and other adverse neonatal outcomes. A 2019 retrospective study from Sweden, for instance, analyzed patterns of CGM data from 186 pregnant women with type 1 diabetes and found significant associations between elevated mean glucose levels (in the second and third trimesters) and both LGA and an adverse neonatal composite outcome (Diabetologia. 2019;62:1143-53).

Elevated TIR was also associated with LGA, but “mean glucose had the strongest association with the rate of LGA,” Dr. Durnwald said.

Similarly, a 2020 subanalysis of the CONCEPTT trial data found that a higher mean glucose at both 24 and 34 weeks of gestation was significantly associated with a greater risk of LGA (Diabetes Care. 2020;43:1178-84), and a smaller 2015 analysis of data from two randomized controlled trials of CGM in pregnant women with type 1 and type 2 diabetes found this association in trimesters 2 and 3 (Diabetes Care. 2015;38;1319-25).

The ADA’s Standards of Care in Diabetes (Diabetes Care. 2024;47:S282-S294) endorse CGM as an adjunctive tool in pregnancy — not as a replacement for all traditional blood glucose monitoring — and advise that the use of CGM-reported mean glucose is superior to the use of estimated A1c, glucose management indicator, and other calculations to estimate A1c. Changes occur in pregnancy, Dr. Durnwald pointed out. “Most experts will identify a [target] mean glucose < 120 mg/dL in those with type 1, but there’s potential to have a mean glucose closer to 100 in certainly our patients with GDM and some of our patients with type 2,” she said. To a lesser extent, researchers have also looked at the effect of CMG-reported glycemic variability on outcomes such as LGA, with at least two studies finding some association, and there has been some research on nocturnal glucose and LGA, Dr. Durnwald said. CGM “gives us the opportunity,” she said, “to think about nocturnal glucose as a possible target” for further optimizing diabetes management during pregnancy.

CGM in Type 2, GDM

CGM in type 2 diabetes in pregnancy was addressed in a recently published systematic review and meta-analysis, which found only three qualifying randomized controlled trials and concluded that CGM use was not associated with improvements in perinatal outcomes, as assessed by LGA and preeclampsia (Am J Obstet Gynecol MFM. 2023;5:100969). “It’s very limited by the small sample size and the fact that most [patients] were using intermittent CGM,” Dr. Durnwald said. “It highlights how important it is to perform larger studies with continuous CGM.”

While the 2024 ADA standards say there are insufficient data to support the use of CGM in all patients with type 2 diabetes or GDM — and that the decision should be individualized “based on treatment regimen, circumstance, preferences, and needs” — real-world access to CGM for type 2, and even a bit for GDM, is improving, she said.

Some insurers require patients to be on insulin, but the trends are such that “we certainly talk about CGM to all our patients with type 2 diabetes and even our patients with GDM,” Dr. Durnwald said in a later interview. “CGMs are being advertised so we definitely have people who ask about them upon diagnosis, and we try to make it work for them.”
 

Is Preventing Maternal Hypoglycemia Possible?

Advancements in technology and pharmacology aimed at optimizing glycemic control — increased adoption of CGM, the use of insulin pump therapy, and the use of more rapid insulin analogs — appear to have had little to no impact on rates of severe maternal hypoglycemia in type 1 diabetes in pregnancy, said Dr. Rosenn, referring to several published studies.

The CONCEPTT study in type 1 diabetes, for instance, “gave us the best data we have on the use of CGM,” but differences in the percentage of patients with severe hypoglycemia and the total number of severe hypoglycemia episodes were basically the same whether patients used CGM or not, he said.

Closed-loop insulin delivery systems have been found in nonpregnant patients with type 1 diabetes to “be helpful in keeping people in range and also possibly [decreasing nocturnal hypoglycemia],” but the systems are not approved for use in pregnancy. “There’s not enough data on use in pregnancy, but probably more important, the algorithms used in the closed-loop systems are not directed to the targets we consider ideal for pregnancy,” Dr. Rosenn said.

In a pilot study of a closed-loop delivery system customized for pregnancies complicated by type 1 diabetes, 10 pregnant women were recruited at 14-32 weeks and, after a 1- to 2-week run-in period using a regular CGM-augmented pump, they used the closed-loop system targeting a daytime glucose of 80-110 mg/dL and nocturnal glucose of 80-100 mg/dL.

Mean TIR (a target range of 63-140 mg/dL) increased from 65% during the run-in period to 79% on the closed-loop system, and there were significant decreases in both time above range and time in the hypoglycemic ranges of < 63 mg/dL and < 54 mg/dL. Hypoglycemic events per week (defined as < 54 mg/dL for over 15 minutes) decreased from 4 to 0.7 (Diabetes Care. 2023;46:1425-31).

The investigators are continuing their research, and there are currently two randomized controlled trials underway examining use of closed-loop systems designed for pregnancy, said Dr. Rosenn, who was involved in feasibility research leading up to the pilot study. “So I’m hopeful we’ll see some encouraging information in the future.”

Maternal hypoglycemia during pregnancy is more common in type 1 diabetes, but it also affects pregnancies complicated by type 2 diabetes and GDM. In addition to the strict glycemic control imposed to improve maternal and fetal outcomes, pregnancy itself plays a role.

Research several decades ago from the Diabetes in Pregnancy Program Project, a prospective cohort in Cincinnati which Dr. Rosenn co-led, documented impaired counterregulatory physiology in pregnancy. Even in nondiabetic patients, there are declines in secretion of glucagon and growth hormone in response to hypoglycemia, for instance. In patients with type 1 diabetes, the diminishment in counterregulatory response is more severe.

Rethinking Intrapartum Care

Guidance for tight blood glucose control during labor and delivery for insulin-treated individuals — as reflected in the American College of Obstetricians and Gynecologists Practice Bulletin No. 201 on Pregestational Diabetes and in recommendations from the United Kingdom’s National Institute for Health and Care Excellence (NICE) — is based on small case series and overall “poor-quality” evidence that more recent research has failed to back up, Dr. Bartal said.

A systematic review published in 2018, for example, concluded there is a paucity of high-quality data supporting the association of glucose during labor and delivery with neonatal hypoglycemia in pregnancies complicated by diabetes (Diabet Med. 2018;35:173-83). And in a subsequent retrospective cohort study of pregnant women with type 1/type 2/GDM and their neonates, the same investigators reported no difference in the target glucose in labor between those with and without neonatal hypotension, after adjustment for important neonatal factors such as LGA and preterm delivery (Diabet Med. 2020;37:138-46).

Also exemplifying the body of research, Dr. Bartal said, is another single-center retrospective study published in 2020 that evaluated outcomes in the years before and after the institution of a formal intrapartum insulin regimen (a standardized protocol for titration of insulin and glucose infusions) for women with pregestational or gestational diabetes. The protocol was associated with improved maternal glucose control, but an increased frequency of neonatal hypoglycemia (Obstet Gynecol. 2020;136:411-6).

Her own group at the University of Texas in Houston looked retrospectively at 233 insulin-treated pregnancies complicated by type 2 diabetes and found no significant difference in the rate of neonatal hypoglycemia between those placed on a drip and those who were not, Dr. Bartal said. Over 40% of the newborns had hypoglycemia; it occurred irrespective of the route of delivery as well (J Matern Fetal Neonatal Med. 2022;35:7445-51).

Only two published randomized controlled trials have evaluated blood sugar control in labor, she said. The first, published in 2006, compared a continuous insulin drip with a rotation of glucose and non–glucose-containing fluids in insulin-requiring diabetes and found no differences in maternal blood glucose (the primary outcome) and a similar risk of neonatal hypoglycemia (Am J Obstet Gynecol. 2006;195;1095-9).

The second RCT, published in 2019, evaluated tight versus liberalized control (60-100 mg/dL, checking every hour, versus 60-120 mg/dL, checking every 4 hours) in laboring women with GDM. The first neonatal blood glucose level was similar in both groups, while the mean neonatal blood glucose level in the first 24 hours of life was lower with tight control (54 vs 58 mg/dL, P = .49) (Obstet Gynecol. 2019;133:1171-7). Findings from a new RCT conducted at the University of Texas in Houston of usual care versus more permissive glucose control will be presented at the SMFM Pregnancy Meeting in February 2024, she said.

Neonatal hypoglycemia is associated with increased risk of NICU admission, “but it’s also associated with possible long-term developmental deficit,” Dr. Bartal said, with the risk highest in children exposed to severe, recurrent, or clinically undetected hypoglycemia. Research has documented significantly increased risks of low executive function and visual motor function, for instance, in children who experienced neonatal hypoglycemia.

The risk of neonatal hypoglycemia has been linked to a variety of factors outside of the intrapartum period such as diabetes control and weight gain during pregnancy, neonatal birth weight/LGA, neonatal adiposity, gestational age at delivery, maternal body mass index, smoking, and diabetes control prior to pregnancy, Dr. Bartal noted. Also challenging is the reality that neonatal hypoglycemia as a research outcome is not standardized; definitions have varied across studies.

Tight intrapartum control comes with “costs,” from close monitoring of labor to increased resource utilization, and it may affect the labor experience/satisfaction, Dr. Bartal said. “But furthermore,” she said, “there are studies coming out, especially in the anesthesiology journals, that show there may be possible harm,” such as the risk of maternal and neonatal hyponatremia, and maternal hypoglycemia. A 2016 editorial in Anaesthesia (2016;71:750) describes these concerns, she noted.

“I do think we need to rethink our current recommendations,” she said.

Dr. Durnwald reported serving on the Dexcom GDM advisory board and receiving funding from United Health Group and the Helmsley Charitable Trust. Dr. Bartal and Dr. Rosenn reported no conflicts of interest.

WASHINGTON — Continuous glucose monitoring (CGM) is widely used during pregnancy for individuals with type 1 diabetes — with pregnancy-specific target metrics now chosen and benefits on perinatal outcomes demonstrated — but more research is needed to elucidate its role in the growing population of pregnant people with type 2 diabetes and gestational diabetes (GDM). And overall, there are still “many more questions unanswered about CGM use in pregnancy than what we have answered,” Celeste Durnwald, MD, said at the biennial meeting of the Diabetes in Pregnancy Study Group of North America.

There’s much to learn about how to best interpret “the detailed and complex data that CGM provides,” and what targets in addition to time in range (TIR) are most important, said Dr. Durnwald, director of the perinatal diabetes program and associate professor of ob.gyn. at the Hospital of the University of Pennsylvania, Philadelphia, in a presentation on CGM.

Among other questions are whether fasting glucose is “as important in the era of CGM,” and whether there should be different glycemic targets for nocturnal versus daytime TIR, she said. Moreover, questions justifiably remain about whether the TIR targets for type 1 diabetes in pregnancy are indeed optimal, she said in a discussion period.

Ongoing research is looking at whether CGM can motivate and guide patients with GDM through diet and lifestyle changes such that “we can see changes in amounts of medication we use,” Dr. Durnwald noted in her presentation. “There’s a whole breadth of research looking at whether CGM can help predict diagnosis of GDM, large for gestational age, or preeclampsia, and what are the targets.”

Maternal hypoglycemia during pregnancy — a time when strict glycemic control is recommended to reduce the risk of congenital malformations and other fetal and neonatal morbidity — remains a concern in type 1 diabetes, even with widespread use of CGM in this population, said Barak Rosenn, MD, during a presentation on glycemic control in type 1 diabetes.

A pilot study of a newly designed pregnancy-specific closed-loop insulin delivery system, published last year (Diabetes Care. 2023;46:1425-31), has offered the first “really encouraging information about the ability to use our most up-to-date technology to help our type 1 patients maintain strict control and at the same time decrease their risk of severe hypoglycemia,” said Dr. Rosenn, a maternal-fetal medicine specialist at the Jersey City Medical Center, Jersey City, New Jersey.

Guidance for tight intrapartum glucose control, meanwhile, has been backed by little evidence, said Michal Fishel Bartal, MD, MS, and some recent studies and reviews have shown little to no effect of such tight control on neonatal hypoglycemia, which is the aim of the guidance.

“We need to reexamine current recommendations,” said Dr. Bartal, assistant professor in the division of maternal-fetal medicine at the University of Texas Health Science Center, Houston, during a presentation on intrapartum care. “There’s very limited evidence-based data for the way we manage people with diabetes [during labor and delivery].”

The Knowns And Unknowns of CGM in Pregnancy

The multicenter, international CONCEPTT trial (Continuous Glucose Monitoring in Pregnant Women With Type 1 Diabetes), published in 2017, was the first trial to demonstrate improvements in perinatal outcomes, and it “brought CGM to the forefront in terms of widespread use,” Dr. Durnwald said.

The trial randomized more than 300 patients with type 1 diabetes who were pregnant or planning pregnancy (both users of insulin pumps and users of multiple insulin injections) to continuous, real-time CGM in addition to finger-stick glucose monitoring, or standard finger-stick glucose tests alone. In addition to small improvements in A1c and 7% more TIR (without an increase in hypoglycemia), pregnant CGM users had reductions in large-for-gestational age (LGA) births (53% vs 69%, P = .0489), neonatal intensive care admissions lasting more than 24 hours, and severe neonatal hypoglycemia.

Numbers needed to treat to prevent adverse outcomes in the CONCEPTT trial were six for LGA, six for NICU admission, and eight for neonatal hypoglycemia.

Data from the CONCEPTT trial featured prominently in the development of consensus recommendations for CGM targets in pregnancy by an international expert panel endorsed by the American Diabetes Association. In its 2019 report, the group recommended a target range of 63-140 mg/dL for type 1 and type 2 diabetes during pregnancy (compared with 70-180 mg/dL outside of pregnancy), and a TIR > 70% for pregnant people with type 1 diabetes. (Targets for time below range and time above range are also defined for type 1.)

More data are needed, the group said, in order to recommend TIR targets for type 2 diabetes in pregnancy or GDM (Diabetes Care. 2019;42:1593-603). “Many argue,” Dr. Durnwald said, “that there could be more stringent targets for those at less risk for [maternal] hypoglycemia, especially our GDM population.”

There’s a question of whether even higher TIR would further improve perinatal outcomes, she said, “or will we reach a threshold where higher TIR doesn’t get us a [further] reduction in LGA or preeclampsia.”

And while TIR is “certainly our buzzword,” lower mean glucose levels have also been associated with a lower risk of LGA and other adverse neonatal outcomes. A 2019 retrospective study from Sweden, for instance, analyzed patterns of CGM data from 186 pregnant women with type 1 diabetes and found significant associations between elevated mean glucose levels (in the second and third trimesters) and both LGA and an adverse neonatal composite outcome (Diabetologia. 2019;62:1143-53).

Elevated TIR was also associated with LGA, but “mean glucose had the strongest association with the rate of LGA,” Dr. Durnwald said.

Similarly, a 2020 subanalysis of the CONCEPTT trial data found that a higher mean glucose at both 24 and 34 weeks of gestation was significantly associated with a greater risk of LGA (Diabetes Care. 2020;43:1178-84), and a smaller 2015 analysis of data from two randomized controlled trials of CGM in pregnant women with type 1 and type 2 diabetes found this association in trimesters 2 and 3 (Diabetes Care. 2015;38;1319-25).

The ADA’s Standards of Care in Diabetes (Diabetes Care. 2024;47:S282-S294) endorse CGM as an adjunctive tool in pregnancy — not as a replacement for all traditional blood glucose monitoring — and advise that the use of CGM-reported mean glucose is superior to the use of estimated A1c, glucose management indicator, and other calculations to estimate A1c. Changes occur in pregnancy, Dr. Durnwald pointed out. “Most experts will identify a [target] mean glucose < 120 mg/dL in those with type 1, but there’s potential to have a mean glucose closer to 100 in certainly our patients with GDM and some of our patients with type 2,” she said. To a lesser extent, researchers have also looked at the effect of CMG-reported glycemic variability on outcomes such as LGA, with at least two studies finding some association, and there has been some research on nocturnal glucose and LGA, Dr. Durnwald said. CGM “gives us the opportunity,” she said, “to think about nocturnal glucose as a possible target” for further optimizing diabetes management during pregnancy.

CGM in Type 2, GDM

CGM in type 2 diabetes in pregnancy was addressed in a recently published systematic review and meta-analysis, which found only three qualifying randomized controlled trials and concluded that CGM use was not associated with improvements in perinatal outcomes, as assessed by LGA and preeclampsia (Am J Obstet Gynecol MFM. 2023;5:100969). “It’s very limited by the small sample size and the fact that most [patients] were using intermittent CGM,” Dr. Durnwald said. “It highlights how important it is to perform larger studies with continuous CGM.”

While the 2024 ADA standards say there are insufficient data to support the use of CGM in all patients with type 2 diabetes or GDM — and that the decision should be individualized “based on treatment regimen, circumstance, preferences, and needs” — real-world access to CGM for type 2, and even a bit for GDM, is improving, she said.

Some insurers require patients to be on insulin, but the trends are such that “we certainly talk about CGM to all our patients with type 2 diabetes and even our patients with GDM,” Dr. Durnwald said in a later interview. “CGMs are being advertised so we definitely have people who ask about them upon diagnosis, and we try to make it work for them.”
 

Is Preventing Maternal Hypoglycemia Possible?

Advancements in technology and pharmacology aimed at optimizing glycemic control — increased adoption of CGM, the use of insulin pump therapy, and the use of more rapid insulin analogs — appear to have had little to no impact on rates of severe maternal hypoglycemia in type 1 diabetes in pregnancy, said Dr. Rosenn, referring to several published studies.

The CONCEPTT study in type 1 diabetes, for instance, “gave us the best data we have on the use of CGM,” but differences in the percentage of patients with severe hypoglycemia and the total number of severe hypoglycemia episodes were basically the same whether patients used CGM or not, he said.

Closed-loop insulin delivery systems have been found in nonpregnant patients with type 1 diabetes to “be helpful in keeping people in range and also possibly [decreasing nocturnal hypoglycemia],” but the systems are not approved for use in pregnancy. “There’s not enough data on use in pregnancy, but probably more important, the algorithms used in the closed-loop systems are not directed to the targets we consider ideal for pregnancy,” Dr. Rosenn said.

In a pilot study of a closed-loop delivery system customized for pregnancies complicated by type 1 diabetes, 10 pregnant women were recruited at 14-32 weeks and, after a 1- to 2-week run-in period using a regular CGM-augmented pump, they used the closed-loop system targeting a daytime glucose of 80-110 mg/dL and nocturnal glucose of 80-100 mg/dL.

Mean TIR (a target range of 63-140 mg/dL) increased from 65% during the run-in period to 79% on the closed-loop system, and there were significant decreases in both time above range and time in the hypoglycemic ranges of < 63 mg/dL and < 54 mg/dL. Hypoglycemic events per week (defined as < 54 mg/dL for over 15 minutes) decreased from 4 to 0.7 (Diabetes Care. 2023;46:1425-31).

The investigators are continuing their research, and there are currently two randomized controlled trials underway examining use of closed-loop systems designed for pregnancy, said Dr. Rosenn, who was involved in feasibility research leading up to the pilot study. “So I’m hopeful we’ll see some encouraging information in the future.”

Maternal hypoglycemia during pregnancy is more common in type 1 diabetes, but it also affects pregnancies complicated by type 2 diabetes and GDM. In addition to the strict glycemic control imposed to improve maternal and fetal outcomes, pregnancy itself plays a role.

Research several decades ago from the Diabetes in Pregnancy Program Project, a prospective cohort in Cincinnati which Dr. Rosenn co-led, documented impaired counterregulatory physiology in pregnancy. Even in nondiabetic patients, there are declines in secretion of glucagon and growth hormone in response to hypoglycemia, for instance. In patients with type 1 diabetes, the diminishment in counterregulatory response is more severe.

Rethinking Intrapartum Care

Guidance for tight blood glucose control during labor and delivery for insulin-treated individuals — as reflected in the American College of Obstetricians and Gynecologists Practice Bulletin No. 201 on Pregestational Diabetes and in recommendations from the United Kingdom’s National Institute for Health and Care Excellence (NICE) — is based on small case series and overall “poor-quality” evidence that more recent research has failed to back up, Dr. Bartal said.

A systematic review published in 2018, for example, concluded there is a paucity of high-quality data supporting the association of glucose during labor and delivery with neonatal hypoglycemia in pregnancies complicated by diabetes (Diabet Med. 2018;35:173-83). And in a subsequent retrospective cohort study of pregnant women with type 1/type 2/GDM and their neonates, the same investigators reported no difference in the target glucose in labor between those with and without neonatal hypotension, after adjustment for important neonatal factors such as LGA and preterm delivery (Diabet Med. 2020;37:138-46).

Also exemplifying the body of research, Dr. Bartal said, is another single-center retrospective study published in 2020 that evaluated outcomes in the years before and after the institution of a formal intrapartum insulin regimen (a standardized protocol for titration of insulin and glucose infusions) for women with pregestational or gestational diabetes. The protocol was associated with improved maternal glucose control, but an increased frequency of neonatal hypoglycemia (Obstet Gynecol. 2020;136:411-6).

Her own group at the University of Texas in Houston looked retrospectively at 233 insulin-treated pregnancies complicated by type 2 diabetes and found no significant difference in the rate of neonatal hypoglycemia between those placed on a drip and those who were not, Dr. Bartal said. Over 40% of the newborns had hypoglycemia; it occurred irrespective of the route of delivery as well (J Matern Fetal Neonatal Med. 2022;35:7445-51).

Only two published randomized controlled trials have evaluated blood sugar control in labor, she said. The first, published in 2006, compared a continuous insulin drip with a rotation of glucose and non–glucose-containing fluids in insulin-requiring diabetes and found no differences in maternal blood glucose (the primary outcome) and a similar risk of neonatal hypoglycemia (Am J Obstet Gynecol. 2006;195;1095-9).

The second RCT, published in 2019, evaluated tight versus liberalized control (60-100 mg/dL, checking every hour, versus 60-120 mg/dL, checking every 4 hours) in laboring women with GDM. The first neonatal blood glucose level was similar in both groups, while the mean neonatal blood glucose level in the first 24 hours of life was lower with tight control (54 vs 58 mg/dL, P = .49) (Obstet Gynecol. 2019;133:1171-7). Findings from a new RCT conducted at the University of Texas in Houston of usual care versus more permissive glucose control will be presented at the SMFM Pregnancy Meeting in February 2024, she said.

Neonatal hypoglycemia is associated with increased risk of NICU admission, “but it’s also associated with possible long-term developmental deficit,” Dr. Bartal said, with the risk highest in children exposed to severe, recurrent, or clinically undetected hypoglycemia. Research has documented significantly increased risks of low executive function and visual motor function, for instance, in children who experienced neonatal hypoglycemia.

The risk of neonatal hypoglycemia has been linked to a variety of factors outside of the intrapartum period such as diabetes control and weight gain during pregnancy, neonatal birth weight/LGA, neonatal adiposity, gestational age at delivery, maternal body mass index, smoking, and diabetes control prior to pregnancy, Dr. Bartal noted. Also challenging is the reality that neonatal hypoglycemia as a research outcome is not standardized; definitions have varied across studies.

Tight intrapartum control comes with “costs,” from close monitoring of labor to increased resource utilization, and it may affect the labor experience/satisfaction, Dr. Bartal said. “But furthermore,” she said, “there are studies coming out, especially in the anesthesiology journals, that show there may be possible harm,” such as the risk of maternal and neonatal hyponatremia, and maternal hypoglycemia. A 2016 editorial in Anaesthesia (2016;71:750) describes these concerns, she noted.

“I do think we need to rethink our current recommendations,” she said.

Dr. Durnwald reported serving on the Dexcom GDM advisory board and receiving funding from United Health Group and the Helmsley Charitable Trust. Dr. Bartal and Dr. Rosenn reported no conflicts of interest.

Comorbidities may play a large role in driving poor pregnancy outcomes in pregnant people with certain immune-mediated inflammatory diseases (IMIDs).

In a new study of 12 individual IMIDs, people with rheumatoid arthritis (RA) or inflammatory bowel disease (IBD) did not have signficantly increased risk for preterm birth (PTB) or low birth weight (LBW), compared with people who did not have an IMID, after adjusting for additional chronic conditions and other confounding factors.

The study was published online on February 1 in eClinicalMedicine.

While many studies have explored the relationships between pregnancy outcomes and IMIDs, “the impact of comorbidities on the relation between IMIDs and pregnancy course is insufficiently examined,” the authors wrote. These previous studies also tended to have a small sample size.
 

Pregnancy Outcome Risks Varied Between IMIDs

To remedy this, researchers used electronic health record data from Providence St Joseph Health — a multistate integrated healthcare system — to identify more than 365,000 pregnant people with live births between January 1, 2013, and December 31, 2022. The cohort included more than 5700 people with at least one of 12 IMIDs: Psoriasis, IBD, RA, spondyloarthritis (SpA), multiple sclerosis, systemic lupus erythematosus (SLE), psoriatic arthritis (PsA), antiphospholipid syndrome (APS), Sjögren syndrome (SjS), vasculitis, sarcoidosis, and systemic sclerosis. The study included only live births with a gestational age of 20 weeks or greater.

Researchers compared maternal-fetal health outcomes between the two groups, controlling for comorbidities including diabetes, cardiovascular disease, chronic kidney disease, obesity, and depression. They also accounted for confounding variables including race, age, smoking status, and socioeconomic status.

In total, 83% of people in the IMID group had no immunomodulatory medication prescriptions during their pregnancy. Of the 17% taking medication, 48%-70% continued taking their medication until delivery. Most patients were White, comprising 62.9% of the non-IMID group and 73.1% of the IMID group.

After adjusting for comorbidities, patients with any of the 12 IMIDs had a 10%-20% higher risk for PTB, LBW, small for gestation age (SGA), and cesarean section than did comparators.

But these risks varied between IMIDs. Patients with RA and IBD did not have an increased risk for PTB or LBW. However, when researchers did not control for comorbidities, pregnancy risks were higher and showed statistical significance in these two groups.

“This suggests that for RA and IBD, comorbidities may be a more important factor for adverse outcomes than the underlying autoimmune disease,” senior author Jennifer Hadlock, MD, an associate professor and director of medical data science at the Institute for Systems Biology in Seattle, Washington, said in a video accompanying a press release.

Overall, the analysis found that women with IMIDs were approximately two to three times more likely to have chronic comorbidities than the control group.

Like previous studies, there was a strong association between SLE and APS and poor pregnancy outcomes, even after controlling for confounding factors. Patients with SpA had a 50% increased risk for PTB, while those with SLE and APS had more than a twofold higher risk. Patients with SLE were 90% more likely than comparators to deliver babies with an SGA condition, while RA patients had a 30% higher risk. SLE was the only condition with an increased risk for LBW (relative risk, 3.5). IBD, RA, PsA, SpA, SLE, APS, and SjS were all associated with a higher likelihood of delivery via cesarean section.

“The findings of this study reveal that the associations between IMIDs and adverse pregnancy outcomes are influenced by the specific type of IMIDs and the presence of comorbidities,” the authors wrote.
 

A Large Study, But How Representative Is It?

Asked to comment on the study, Catherine Sims, MD, a rheumatologist at Duke University Medical Center in Durham, North Carolina, noted that the analysis was much larger than many reproductive rheumatology studies, and “their statistics were phenomenal.”

She agreed that “not all autoimmune diseases are created equal when it comes to pregnancy-associated risks.” However, she added that this study’s patient population may not be totally representative of pregnant people with IMIDs or autoimmune diseases.

“We’re making generalizations about autoimmune diseases based on this demographic of White women who are not taking immunosuppression,” she said.

“We know that race and ethnicity play a huge role in pregnancy outcomes, and Black women have higher maternal and fetal morbidity and mortality, which is likely related to systemic racism and biases in the medical system,” she added. “While the study did control for sociodemographic factors, the population studied is not diverse.”

Only 17% of people with IMID in the cohort were on immunosuppressive medication, which could suggest low disease activity in the study population, Dr. Sims said. If the population generally had well-controlled disease, that could have positioned them for better pregnancy outcomes.

The authors noted that their analysis did not have information on IMID disease activity or severity — one of the limitations of the study.

However, the authors argued that the observed low prescription rate during the study may have increased poor pregnancy outcomes.

“Although this reflects real-world care in the population studied, results from this study may show higher risk than might be achieved with recommended care guidelines,” they wrote.

Ultimately, the authors argued that these findings show how co-occurring health conditions can affect pregnancy outcomes in autoimmune diseases, particularly for RA and IBD.

“There is a need to take comorbidities into consideration for guidelines for patients with inflammatory bowel disease and rheumatoid arthritis and when designing future research to investigate maternal health in patients with IMIDs,” they wrote.

The study was funded by the National Institutes of Health. Dr. Sims declared no relevant financial relationships. Dr. Hadlock has received research funding (paid to the institute) from Pfizer, Novartis, Janssen, Bristol-Myers Squibb, and Gilead.

A version of this article first appeared on Medscape.com.

Comorbidities may play a large role in driving poor pregnancy outcomes in pregnant people with certain immune-mediated inflammatory diseases (IMIDs).

In a new study of 12 individual IMIDs, people with rheumatoid arthritis (RA) or inflammatory bowel disease (IBD) did not have signficantly increased risk for preterm birth (PTB) or low birth weight (LBW), compared with people who did not have an IMID, after adjusting for additional chronic conditions and other confounding factors.

The study was published online on February 1 in eClinicalMedicine.

While many studies have explored the relationships between pregnancy outcomes and IMIDs, “the impact of comorbidities on the relation between IMIDs and pregnancy course is insufficiently examined,” the authors wrote. These previous studies also tended to have a small sample size.
 

Pregnancy Outcome Risks Varied Between IMIDs

To remedy this, researchers used electronic health record data from Providence St Joseph Health — a multistate integrated healthcare system — to identify more than 365,000 pregnant people with live births between January 1, 2013, and December 31, 2022. The cohort included more than 5700 people with at least one of 12 IMIDs: Psoriasis, IBD, RA, spondyloarthritis (SpA), multiple sclerosis, systemic lupus erythematosus (SLE), psoriatic arthritis (PsA), antiphospholipid syndrome (APS), Sjögren syndrome (SjS), vasculitis, sarcoidosis, and systemic sclerosis. The study included only live births with a gestational age of 20 weeks or greater.

Researchers compared maternal-fetal health outcomes between the two groups, controlling for comorbidities including diabetes, cardiovascular disease, chronic kidney disease, obesity, and depression. They also accounted for confounding variables including race, age, smoking status, and socioeconomic status.

In total, 83% of people in the IMID group had no immunomodulatory medication prescriptions during their pregnancy. Of the 17% taking medication, 48%-70% continued taking their medication until delivery. Most patients were White, comprising 62.9% of the non-IMID group and 73.1% of the IMID group.

After adjusting for comorbidities, patients with any of the 12 IMIDs had a 10%-20% higher risk for PTB, LBW, small for gestation age (SGA), and cesarean section than did comparators.

But these risks varied between IMIDs. Patients with RA and IBD did not have an increased risk for PTB or LBW. However, when researchers did not control for comorbidities, pregnancy risks were higher and showed statistical significance in these two groups.

“This suggests that for RA and IBD, comorbidities may be a more important factor for adverse outcomes than the underlying autoimmune disease,” senior author Jennifer Hadlock, MD, an associate professor and director of medical data science at the Institute for Systems Biology in Seattle, Washington, said in a video accompanying a press release.

Overall, the analysis found that women with IMIDs were approximately two to three times more likely to have chronic comorbidities than the control group.

Like previous studies, there was a strong association between SLE and APS and poor pregnancy outcomes, even after controlling for confounding factors. Patients with SpA had a 50% increased risk for PTB, while those with SLE and APS had more than a twofold higher risk. Patients with SLE were 90% more likely than comparators to deliver babies with an SGA condition, while RA patients had a 30% higher risk. SLE was the only condition with an increased risk for LBW (relative risk, 3.5). IBD, RA, PsA, SpA, SLE, APS, and SjS were all associated with a higher likelihood of delivery via cesarean section.

“The findings of this study reveal that the associations between IMIDs and adverse pregnancy outcomes are influenced by the specific type of IMIDs and the presence of comorbidities,” the authors wrote.
 

A Large Study, But How Representative Is It?

Asked to comment on the study, Catherine Sims, MD, a rheumatologist at Duke University Medical Center in Durham, North Carolina, noted that the analysis was much larger than many reproductive rheumatology studies, and “their statistics were phenomenal.”

She agreed that “not all autoimmune diseases are created equal when it comes to pregnancy-associated risks.” However, she added that this study’s patient population may not be totally representative of pregnant people with IMIDs or autoimmune diseases.

“We’re making generalizations about autoimmune diseases based on this demographic of White women who are not taking immunosuppression,” she said.

“We know that race and ethnicity play a huge role in pregnancy outcomes, and Black women have higher maternal and fetal morbidity and mortality, which is likely related to systemic racism and biases in the medical system,” she added. “While the study did control for sociodemographic factors, the population studied is not diverse.”

Only 17% of people with IMID in the cohort were on immunosuppressive medication, which could suggest low disease activity in the study population, Dr. Sims said. If the population generally had well-controlled disease, that could have positioned them for better pregnancy outcomes.

The authors noted that their analysis did not have information on IMID disease activity or severity — one of the limitations of the study.

However, the authors argued that the observed low prescription rate during the study may have increased poor pregnancy outcomes.

“Although this reflects real-world care in the population studied, results from this study may show higher risk than might be achieved with recommended care guidelines,” they wrote.

Ultimately, the authors argued that these findings show how co-occurring health conditions can affect pregnancy outcomes in autoimmune diseases, particularly for RA and IBD.

“There is a need to take comorbidities into consideration for guidelines for patients with inflammatory bowel disease and rheumatoid arthritis and when designing future research to investigate maternal health in patients with IMIDs,” they wrote.

The study was funded by the National Institutes of Health. Dr. Sims declared no relevant financial relationships. Dr. Hadlock has received research funding (paid to the institute) from Pfizer, Novartis, Janssen, Bristol-Myers Squibb, and Gilead.

A version of this article first appeared on Medscape.com.

Comorbidities may play a large role in driving poor pregnancy outcomes in pregnant people with certain immune-mediated inflammatory diseases (IMIDs).

In a new study of 12 individual IMIDs, people with rheumatoid arthritis (RA) or inflammatory bowel disease (IBD) did not have signficantly increased risk for preterm birth (PTB) or low birth weight (LBW), compared with people who did not have an IMID, after adjusting for additional chronic conditions and other confounding factors.

The study was published online on February 1 in eClinicalMedicine.

While many studies have explored the relationships between pregnancy outcomes and IMIDs, “the impact of comorbidities on the relation between IMIDs and pregnancy course is insufficiently examined,” the authors wrote. These previous studies also tended to have a small sample size.
 

Pregnancy Outcome Risks Varied Between IMIDs

To remedy this, researchers used electronic health record data from Providence St Joseph Health — a multistate integrated healthcare system — to identify more than 365,000 pregnant people with live births between January 1, 2013, and December 31, 2022. The cohort included more than 5700 people with at least one of 12 IMIDs: Psoriasis, IBD, RA, spondyloarthritis (SpA), multiple sclerosis, systemic lupus erythematosus (SLE), psoriatic arthritis (PsA), antiphospholipid syndrome (APS), Sjögren syndrome (SjS), vasculitis, sarcoidosis, and systemic sclerosis. The study included only live births with a gestational age of 20 weeks or greater.

Researchers compared maternal-fetal health outcomes between the two groups, controlling for comorbidities including diabetes, cardiovascular disease, chronic kidney disease, obesity, and depression. They also accounted for confounding variables including race, age, smoking status, and socioeconomic status.

In total, 83% of people in the IMID group had no immunomodulatory medication prescriptions during their pregnancy. Of the 17% taking medication, 48%-70% continued taking their medication until delivery. Most patients were White, comprising 62.9% of the non-IMID group and 73.1% of the IMID group.

After adjusting for comorbidities, patients with any of the 12 IMIDs had a 10%-20% higher risk for PTB, LBW, small for gestation age (SGA), and cesarean section than did comparators.

But these risks varied between IMIDs. Patients with RA and IBD did not have an increased risk for PTB or LBW. However, when researchers did not control for comorbidities, pregnancy risks were higher and showed statistical significance in these two groups.

“This suggests that for RA and IBD, comorbidities may be a more important factor for adverse outcomes than the underlying autoimmune disease,” senior author Jennifer Hadlock, MD, an associate professor and director of medical data science at the Institute for Systems Biology in Seattle, Washington, said in a video accompanying a press release.

Overall, the analysis found that women with IMIDs were approximately two to three times more likely to have chronic comorbidities than the control group.

Like previous studies, there was a strong association between SLE and APS and poor pregnancy outcomes, even after controlling for confounding factors. Patients with SpA had a 50% increased risk for PTB, while those with SLE and APS had more than a twofold higher risk. Patients with SLE were 90% more likely than comparators to deliver babies with an SGA condition, while RA patients had a 30% higher risk. SLE was the only condition with an increased risk for LBW (relative risk, 3.5). IBD, RA, PsA, SpA, SLE, APS, and SjS were all associated with a higher likelihood of delivery via cesarean section.

“The findings of this study reveal that the associations between IMIDs and adverse pregnancy outcomes are influenced by the specific type of IMIDs and the presence of comorbidities,” the authors wrote.
 

A Large Study, But How Representative Is It?

Asked to comment on the study, Catherine Sims, MD, a rheumatologist at Duke University Medical Center in Durham, North Carolina, noted that the analysis was much larger than many reproductive rheumatology studies, and “their statistics were phenomenal.”

She agreed that “not all autoimmune diseases are created equal when it comes to pregnancy-associated risks.” However, she added that this study’s patient population may not be totally representative of pregnant people with IMIDs or autoimmune diseases.

“We’re making generalizations about autoimmune diseases based on this demographic of White women who are not taking immunosuppression,” she said.

“We know that race and ethnicity play a huge role in pregnancy outcomes, and Black women have higher maternal and fetal morbidity and mortality, which is likely related to systemic racism and biases in the medical system,” she added. “While the study did control for sociodemographic factors, the population studied is not diverse.”

Only 17% of people with IMID in the cohort were on immunosuppressive medication, which could suggest low disease activity in the study population, Dr. Sims said. If the population generally had well-controlled disease, that could have positioned them for better pregnancy outcomes.

The authors noted that their analysis did not have information on IMID disease activity or severity — one of the limitations of the study.

However, the authors argued that the observed low prescription rate during the study may have increased poor pregnancy outcomes.

“Although this reflects real-world care in the population studied, results from this study may show higher risk than might be achieved with recommended care guidelines,” they wrote.

Ultimately, the authors argued that these findings show how co-occurring health conditions can affect pregnancy outcomes in autoimmune diseases, particularly for RA and IBD.

“There is a need to take comorbidities into consideration for guidelines for patients with inflammatory bowel disease and rheumatoid arthritis and when designing future research to investigate maternal health in patients with IMIDs,” they wrote.

The study was funded by the National Institutes of Health. Dr. Sims declared no relevant financial relationships. Dr. Hadlock has received research funding (paid to the institute) from Pfizer, Novartis, Janssen, Bristol-Myers Squibb, and Gilead.

A version of this article first appeared on Medscape.com.

New evidence suggests that nausea and vomiting of pregnancy (NVP) is tied to elevated levels of the fetal placenta–derived hormone GDF15, and targeting the hormone prophylactically may reduce this common gestational condition.

This protein acts on the brainstem to cause emesis, and, significantly, a mother’s prior exposure to it determines the degree of NVP severity she will experience, according to international researchers including Marlena Fejzo, PhD, a clinical assistant professor of population and public Health at Keck School of Medicine, University of Southern California, Los Angeles.

“GDF15 is at the mechanistic heart of NVP and HG [hyperemesis gravidarum],” Dr. Fejzo and colleagues wrote in Nature, pointing to the need for preventive and therapeutic strategies.

Courtesy HER Foundation

“My previous research showed an association between variation in the GDF15 gene and nausea and vomiting of pregnancy and HG, and this study takes it one step further by elucidating the mechanism. It confirms that the nausea and vomiting (N/V) hormone GDF15 is a major cause of NVP and HG,” Dr. Fejzo said.

The etiology of NVP remains poorly understood although it affects up to 80% of pregnancies. In the US, its severe form, HG, is the leading cause of hospitalization in early pregnancy and the second-leading reason for pregnancy hospitalization overall.

The immunoassay-based study showed that the majority of GDF15 in maternal blood during pregnancy comes from the fetal part of the placenta, and confirms previous studies reporting higher levels in pregnancies with more severe NVP, said Dr. Fejzo, who is who is a board member of the Hyperemesis Education and Research Foundation.

“However, what was really fascinating and surprising is that prior to pregnancy the women who have more severe NVP symptoms actually have lower levels of the hormone.”

Although the gene variant linked to HG was previously associated with higher circulating levels in maternal blood, counterintuitively, this new research showed that women with abnormally high levels prior to pregnancy have either no or very little NVP, said Dr. Fejzo. “That suggests that in humans higher levels may lead to a desensitization to the high levels of the hormone in pregnancy. Then we also proved that desensitization can occur in a mouse model.” 

According to Erin Higgins, MD, a clinical assistant professor of obgyn and reproductive biology at the Cleveland Clinic, Cleveland, Ohio, who was not involved in the study, “This is an exciting finding that may help us to better target treatment of N/V in pregnancy. Factors for NVP have been identified, but to my knowledge there has not been a clear etiology.”

Courtesy Cleveland Clinic

Dr. Higgins cautioned, however, that the GDF15 gene seems important in normal placentation, “so it’s not as simple as blocking the gene or its receptor.” But since preconception exposure to GDF15 might decrease nausea and vomiting once a woman is pregnant, prophylactic treatment may be possible, and metformin has been suggested as a possibility, she said.

The study findings emerged from immunoassays on maternal blood samples collected at about 15 weeks (first trimester and early second trimester), from women with NVP (n = 168) or seen at a hospital for HG (n = 57). Results were compared with those from controls having similar characteristics but no significant symptoms.

Interestingly, GDF15 is also associated with cachexia, a condition similar to HG and characterized by loss of appetite and weight loss, Dr. Fejzo noted. “The hormone can be produced by malignant tumors at levels similar to those seen in pregnancy, and symptoms can be reduced by blocking GDF15 or its receptor, GFRAL. Clinical trials are already underway in cancer patients to test this.”

She is seeking funding to test the impact of increasing GDF15 levels prior to pregnancy in patients who previously experienced HG. “I am confident that desensitizing patients by increasing GDF15 prior to pregnancy and by lowering GDF15 levels during pregnancy will work. But we need to make sure we do safety studies and get the dosing and duration right, and that will take some time.”

Desensitization will need testing first in HG, where the risk for adverse maternal and fetal outcomes is high, so the benefit will outweigh any possible risk of testing medication in pregnancy, she continued. “It will take some time before we get to patients with normal NVP, but I do believe eventually the new findings will result in game-changing therapeutics for the condition.”

Dr. Higgins added, “Even if this isn’t the golden ticket, researchers and clinicians are working toward improvements in the treatment of NVP. We’ve already come a long way in recent years with the development of treatment algorithms and the advent of doxylamine/pyridoxine.”

This study was supported primarily by the Medical Research Council UK and National Institute for Health and Care Research UK, with additional support from various research funding organizations, including Novo Nordisk Foundation.

Dr. Fejzo is a paid consultant for Materna Biosciences and NGM Biopharmaceuticals, and a board member and science adviser for the Hyperemesis Education and Research Foundation.

Numerous study co-authors disclosed financial relationships with private-sector companies, including employment and patent ownership.

Dr. Higgins disclosed no competing interests relevant to her comments but is an instructor for Organon.

New evidence suggests that nausea and vomiting of pregnancy (NVP) is tied to elevated levels of the fetal placenta–derived hormone GDF15, and targeting the hormone prophylactically may reduce this common gestational condition.

This protein acts on the brainstem to cause emesis, and, significantly, a mother’s prior exposure to it determines the degree of NVP severity she will experience, according to international researchers including Marlena Fejzo, PhD, a clinical assistant professor of population and public Health at Keck School of Medicine, University of Southern California, Los Angeles.

“GDF15 is at the mechanistic heart of NVP and HG [hyperemesis gravidarum],” Dr. Fejzo and colleagues wrote in Nature, pointing to the need for preventive and therapeutic strategies.

Courtesy HER Foundation

“My previous research showed an association between variation in the GDF15 gene and nausea and vomiting of pregnancy and HG, and this study takes it one step further by elucidating the mechanism. It confirms that the nausea and vomiting (N/V) hormone GDF15 is a major cause of NVP and HG,” Dr. Fejzo said.

The etiology of NVP remains poorly understood although it affects up to 80% of pregnancies. In the US, its severe form, HG, is the leading cause of hospitalization in early pregnancy and the second-leading reason for pregnancy hospitalization overall.

The immunoassay-based study showed that the majority of GDF15 in maternal blood during pregnancy comes from the fetal part of the placenta, and confirms previous studies reporting higher levels in pregnancies with more severe NVP, said Dr. Fejzo, who is who is a board member of the Hyperemesis Education and Research Foundation.

“However, what was really fascinating and surprising is that prior to pregnancy the women who have more severe NVP symptoms actually have lower levels of the hormone.”

Although the gene variant linked to HG was previously associated with higher circulating levels in maternal blood, counterintuitively, this new research showed that women with abnormally high levels prior to pregnancy have either no or very little NVP, said Dr. Fejzo. “That suggests that in humans higher levels may lead to a desensitization to the high levels of the hormone in pregnancy. Then we also proved that desensitization can occur in a mouse model.” 

According to Erin Higgins, MD, a clinical assistant professor of obgyn and reproductive biology at the Cleveland Clinic, Cleveland, Ohio, who was not involved in the study, “This is an exciting finding that may help us to better target treatment of N/V in pregnancy. Factors for NVP have been identified, but to my knowledge there has not been a clear etiology.”

Courtesy Cleveland Clinic

Dr. Higgins cautioned, however, that the GDF15 gene seems important in normal placentation, “so it’s not as simple as blocking the gene or its receptor.” But since preconception exposure to GDF15 might decrease nausea and vomiting once a woman is pregnant, prophylactic treatment may be possible, and metformin has been suggested as a possibility, she said.

The study findings emerged from immunoassays on maternal blood samples collected at about 15 weeks (first trimester and early second trimester), from women with NVP (n = 168) or seen at a hospital for HG (n = 57). Results were compared with those from controls having similar characteristics but no significant symptoms.

Interestingly, GDF15 is also associated with cachexia, a condition similar to HG and characterized by loss of appetite and weight loss, Dr. Fejzo noted. “The hormone can be produced by malignant tumors at levels similar to those seen in pregnancy, and symptoms can be reduced by blocking GDF15 or its receptor, GFRAL. Clinical trials are already underway in cancer patients to test this.”

She is seeking funding to test the impact of increasing GDF15 levels prior to pregnancy in patients who previously experienced HG. “I am confident that desensitizing patients by increasing GDF15 prior to pregnancy and by lowering GDF15 levels during pregnancy will work. But we need to make sure we do safety studies and get the dosing and duration right, and that will take some time.”

Desensitization will need testing first in HG, where the risk for adverse maternal and fetal outcomes is high, so the benefit will outweigh any possible risk of testing medication in pregnancy, she continued. “It will take some time before we get to patients with normal NVP, but I do believe eventually the new findings will result in game-changing therapeutics for the condition.”

Dr. Higgins added, “Even if this isn’t the golden ticket, researchers and clinicians are working toward improvements in the treatment of NVP. We’ve already come a long way in recent years with the development of treatment algorithms and the advent of doxylamine/pyridoxine.”

This study was supported primarily by the Medical Research Council UK and National Institute for Health and Care Research UK, with additional support from various research funding organizations, including Novo Nordisk Foundation.

Dr. Fejzo is a paid consultant for Materna Biosciences and NGM Biopharmaceuticals, and a board member and science adviser for the Hyperemesis Education and Research Foundation.

Numerous study co-authors disclosed financial relationships with private-sector companies, including employment and patent ownership.

Dr. Higgins disclosed no competing interests relevant to her comments but is an instructor for Organon.

New evidence suggests that nausea and vomiting of pregnancy (NVP) is tied to elevated levels of the fetal placenta–derived hormone GDF15, and targeting the hormone prophylactically may reduce this common gestational condition.

This protein acts on the brainstem to cause emesis, and, significantly, a mother’s prior exposure to it determines the degree of NVP severity she will experience, according to international researchers including Marlena Fejzo, PhD, a clinical assistant professor of population and public Health at Keck School of Medicine, University of Southern California, Los Angeles.

“GDF15 is at the mechanistic heart of NVP and HG [hyperemesis gravidarum],” Dr. Fejzo and colleagues wrote in Nature, pointing to the need for preventive and therapeutic strategies.

Courtesy HER Foundation

“My previous research showed an association between variation in the GDF15 gene and nausea and vomiting of pregnancy and HG, and this study takes it one step further by elucidating the mechanism. It confirms that the nausea and vomiting (N/V) hormone GDF15 is a major cause of NVP and HG,” Dr. Fejzo said.

The etiology of NVP remains poorly understood although it affects up to 80% of pregnancies. In the US, its severe form, HG, is the leading cause of hospitalization in early pregnancy and the second-leading reason for pregnancy hospitalization overall.

The immunoassay-based study showed that the majority of GDF15 in maternal blood during pregnancy comes from the fetal part of the placenta, and confirms previous studies reporting higher levels in pregnancies with more severe NVP, said Dr. Fejzo, who is who is a board member of the Hyperemesis Education and Research Foundation.

“However, what was really fascinating and surprising is that prior to pregnancy the women who have more severe NVP symptoms actually have lower levels of the hormone.”

Although the gene variant linked to HG was previously associated with higher circulating levels in maternal blood, counterintuitively, this new research showed that women with abnormally high levels prior to pregnancy have either no or very little NVP, said Dr. Fejzo. “That suggests that in humans higher levels may lead to a desensitization to the high levels of the hormone in pregnancy. Then we also proved that desensitization can occur in a mouse model.” 

According to Erin Higgins, MD, a clinical assistant professor of obgyn and reproductive biology at the Cleveland Clinic, Cleveland, Ohio, who was not involved in the study, “This is an exciting finding that may help us to better target treatment of N/V in pregnancy. Factors for NVP have been identified, but to my knowledge there has not been a clear etiology.”

Courtesy Cleveland Clinic

Dr. Higgins cautioned, however, that the GDF15 gene seems important in normal placentation, “so it’s not as simple as blocking the gene or its receptor.” But since preconception exposure to GDF15 might decrease nausea and vomiting once a woman is pregnant, prophylactic treatment may be possible, and metformin has been suggested as a possibility, she said.

The study findings emerged from immunoassays on maternal blood samples collected at about 15 weeks (first trimester and early second trimester), from women with NVP (n = 168) or seen at a hospital for HG (n = 57). Results were compared with those from controls having similar characteristics but no significant symptoms.

Interestingly, GDF15 is also associated with cachexia, a condition similar to HG and characterized by loss of appetite and weight loss, Dr. Fejzo noted. “The hormone can be produced by malignant tumors at levels similar to those seen in pregnancy, and symptoms can be reduced by blocking GDF15 or its receptor, GFRAL. Clinical trials are already underway in cancer patients to test this.”

She is seeking funding to test the impact of increasing GDF15 levels prior to pregnancy in patients who previously experienced HG. “I am confident that desensitizing patients by increasing GDF15 prior to pregnancy and by lowering GDF15 levels during pregnancy will work. But we need to make sure we do safety studies and get the dosing and duration right, and that will take some time.”

Desensitization will need testing first in HG, where the risk for adverse maternal and fetal outcomes is high, so the benefit will outweigh any possible risk of testing medication in pregnancy, she continued. “It will take some time before we get to patients with normal NVP, but I do believe eventually the new findings will result in game-changing therapeutics for the condition.”

Dr. Higgins added, “Even if this isn’t the golden ticket, researchers and clinicians are working toward improvements in the treatment of NVP. We’ve already come a long way in recent years with the development of treatment algorithms and the advent of doxylamine/pyridoxine.”

This study was supported primarily by the Medical Research Council UK and National Institute for Health and Care Research UK, with additional support from various research funding organizations, including Novo Nordisk Foundation.

Dr. Fejzo is a paid consultant for Materna Biosciences and NGM Biopharmaceuticals, and a board member and science adviser for the Hyperemesis Education and Research Foundation.

Numerous study co-authors disclosed financial relationships with private-sector companies, including employment and patent ownership.

Dr. Higgins disclosed no competing interests relevant to her comments but is an instructor for Organon.

If a pregnant woman contracts rubella in the first 17 weeks of pregnancy, then the risk for congenital rubella in the newborn — which may entail spontaneous abortion, intrauterine death, or severe fetal malformations — is as high as 80%. This risk once frightened patients and clinicians in Italy. Thanks to widespread population vaccination, however, the World Health Organization declared the elimination of endemic transmission of rubella in Italy in 2021. The Italian National Institute of Health took note, and the recent update of the Guidelines for the Management of Physiological Pregnancy no longer recommends offering rubella screening to all pregnant women.

The Rubeo Test

The rubeo test, an analysis for detecting antibodies in the blood produced by vaccination or a past rubella infection, traditionally forms part of the examination package that every doctor prescribes to expectant patients at the beginning of pregnancy. If the test shows that the woman is not vaccinated and has never encountered the virus, making her susceptible to the risk for infection, according to the previous edition of the Guidelines, then the test should be repeated at 17 weeks of gestation. The purpose is to detect any rubella contracted during pregnancy and offer the woman multidisciplinary counseling in the case of a high risk for severe fetal damage. Infection contracted after the 17th week, however, poses only a minimal risk for congenital deafness. There is no treatment to prevent vertical transmission in case of infection during pregnancy.

For women at risk for infection, the old Guidelines also recommended planning vaccination postnatally, with the prospect of protecting future pregnancies. Rubella vaccination is contraindicated during pregnancy because the vaccine could be teratogenic.

Recommendation Update

In the early ‘90s, universal vaccination against rubella for newborns was introduced in Italy. It became one of the 10 mandatory pediatric vaccinations in 2017. In June 2022, the Ministry of Health reported a vaccination coverage of 93.8% among children aged 24 months, a coverage of 93.3% for the first dose, and a coverage of 89.0% for the second dose in the 2003 birth cohort.

“Rubella is a notifiable disease, and in 2013, the newly activated national surveillance system detected one case of congenital rubella per 100,000 newborns. From 2018 onward, no cases have been reported,” said Vittorio Basevi, a gynecologist of the Perinatal Technical-Scientific Advisory Commission in the Emilia Romagna Region and coordinator of the Technical-Scientific Committee that developed the updated Guidelines. “Thanks to extensive vaccination coverage, the infection no longer circulates in Italy. Based on these data, we decided not to offer screening to pregnant women anymore.”

The recommendation to offer rubella vaccination post partum to women without documentation of two doses or previous infection remains confirmed.

Patients Born Abroad 

How should one handle the care of a pregnant woman born in a country where universal rubella vaccination is not provided? The likelihood that she is susceptible to infection is higher than the that of the general Italian population. “On the other hand, since the virus no longer circulates in our country, the probability of contracting the virus during pregnancy is negligible, unless she has recently traveled to her country of origin or come into contact with family members who recently arrived in Italy,” said Dr. Basevi. “The Guidelines refer to offering screening to all pregnant women. In specific cases, it is up to the treating physician to adopt the conduct they deem appropriate in science and conscience.”

This article was translated from Univadis Italy, which is part of the Medscape Professional Network. A version of this article appeared on Medscape.com.

If a pregnant woman contracts rubella in the first 17 weeks of pregnancy, then the risk for congenital rubella in the newborn — which may entail spontaneous abortion, intrauterine death, or severe fetal malformations — is as high as 80%. This risk once frightened patients and clinicians in Italy. Thanks to widespread population vaccination, however, the World Health Organization declared the elimination of endemic transmission of rubella in Italy in 2021. The Italian National Institute of Health took note, and the recent update of the Guidelines for the Management of Physiological Pregnancy no longer recommends offering rubella screening to all pregnant women.

The Rubeo Test

The rubeo test, an analysis for detecting antibodies in the blood produced by vaccination or a past rubella infection, traditionally forms part of the examination package that every doctor prescribes to expectant patients at the beginning of pregnancy. If the test shows that the woman is not vaccinated and has never encountered the virus, making her susceptible to the risk for infection, according to the previous edition of the Guidelines, then the test should be repeated at 17 weeks of gestation. The purpose is to detect any rubella contracted during pregnancy and offer the woman multidisciplinary counseling in the case of a high risk for severe fetal damage. Infection contracted after the 17th week, however, poses only a minimal risk for congenital deafness. There is no treatment to prevent vertical transmission in case of infection during pregnancy.

For women at risk for infection, the old Guidelines also recommended planning vaccination postnatally, with the prospect of protecting future pregnancies. Rubella vaccination is contraindicated during pregnancy because the vaccine could be teratogenic.

Recommendation Update

In the early ‘90s, universal vaccination against rubella for newborns was introduced in Italy. It became one of the 10 mandatory pediatric vaccinations in 2017. In June 2022, the Ministry of Health reported a vaccination coverage of 93.8% among children aged 24 months, a coverage of 93.3% for the first dose, and a coverage of 89.0% for the second dose in the 2003 birth cohort.

“Rubella is a notifiable disease, and in 2013, the newly activated national surveillance system detected one case of congenital rubella per 100,000 newborns. From 2018 onward, no cases have been reported,” said Vittorio Basevi, a gynecologist of the Perinatal Technical-Scientific Advisory Commission in the Emilia Romagna Region and coordinator of the Technical-Scientific Committee that developed the updated Guidelines. “Thanks to extensive vaccination coverage, the infection no longer circulates in Italy. Based on these data, we decided not to offer screening to pregnant women anymore.”

The recommendation to offer rubella vaccination post partum to women without documentation of two doses or previous infection remains confirmed.

Patients Born Abroad 

How should one handle the care of a pregnant woman born in a country where universal rubella vaccination is not provided? The likelihood that she is susceptible to infection is higher than the that of the general Italian population. “On the other hand, since the virus no longer circulates in our country, the probability of contracting the virus during pregnancy is negligible, unless she has recently traveled to her country of origin or come into contact with family members who recently arrived in Italy,” said Dr. Basevi. “The Guidelines refer to offering screening to all pregnant women. In specific cases, it is up to the treating physician to adopt the conduct they deem appropriate in science and conscience.”

This article was translated from Univadis Italy, which is part of the Medscape Professional Network. A version of this article appeared on Medscape.com.

If a pregnant woman contracts rubella in the first 17 weeks of pregnancy, then the risk for congenital rubella in the newborn — which may entail spontaneous abortion, intrauterine death, or severe fetal malformations — is as high as 80%. This risk once frightened patients and clinicians in Italy. Thanks to widespread population vaccination, however, the World Health Organization declared the elimination of endemic transmission of rubella in Italy in 2021. The Italian National Institute of Health took note, and the recent update of the Guidelines for the Management of Physiological Pregnancy no longer recommends offering rubella screening to all pregnant women.

The Rubeo Test

The rubeo test, an analysis for detecting antibodies in the blood produced by vaccination or a past rubella infection, traditionally forms part of the examination package that every doctor prescribes to expectant patients at the beginning of pregnancy. If the test shows that the woman is not vaccinated and has never encountered the virus, making her susceptible to the risk for infection, according to the previous edition of the Guidelines, then the test should be repeated at 17 weeks of gestation. The purpose is to detect any rubella contracted during pregnancy and offer the woman multidisciplinary counseling in the case of a high risk for severe fetal damage. Infection contracted after the 17th week, however, poses only a minimal risk for congenital deafness. There is no treatment to prevent vertical transmission in case of infection during pregnancy.

For women at risk for infection, the old Guidelines also recommended planning vaccination postnatally, with the prospect of protecting future pregnancies. Rubella vaccination is contraindicated during pregnancy because the vaccine could be teratogenic.

Recommendation Update

In the early ‘90s, universal vaccination against rubella for newborns was introduced in Italy. It became one of the 10 mandatory pediatric vaccinations in 2017. In June 2022, the Ministry of Health reported a vaccination coverage of 93.8% among children aged 24 months, a coverage of 93.3% for the first dose, and a coverage of 89.0% for the second dose in the 2003 birth cohort.

“Rubella is a notifiable disease, and in 2013, the newly activated national surveillance system detected one case of congenital rubella per 100,000 newborns. From 2018 onward, no cases have been reported,” said Vittorio Basevi, a gynecologist of the Perinatal Technical-Scientific Advisory Commission in the Emilia Romagna Region and coordinator of the Technical-Scientific Committee that developed the updated Guidelines. “Thanks to extensive vaccination coverage, the infection no longer circulates in Italy. Based on these data, we decided not to offer screening to pregnant women anymore.”

The recommendation to offer rubella vaccination post partum to women without documentation of two doses or previous infection remains confirmed.

Patients Born Abroad 

How should one handle the care of a pregnant woman born in a country where universal rubella vaccination is not provided? The likelihood that she is susceptible to infection is higher than the that of the general Italian population. “On the other hand, since the virus no longer circulates in our country, the probability of contracting the virus during pregnancy is negligible, unless she has recently traveled to her country of origin or come into contact with family members who recently arrived in Italy,” said Dr. Basevi. “The Guidelines refer to offering screening to all pregnant women. In specific cases, it is up to the treating physician to adopt the conduct they deem appropriate in science and conscience.”

This article was translated from Univadis Italy, which is part of the Medscape Professional Network. A version of this article appeared on Medscape.com.

Mothers on vegan diets during pregnancy may give birth to infants with lower mean birth weights than those of omnivorous mothers and may also have a greater risk of preeclampsia, a prospective study of Danish pregnant women suggests.

According to researchers led by Signe Hedegaard, MD, of the department of obstetrics and Gynecology at Rigshospitalet, Juliane Marie Center, University of Copenhagen, low protein intake may lie behind the observed association with birth weight. The report was published in Acta Obstetricia et Gynecologica Scandinavica.

While vegan-identifying mothers were very few in number, the authors conceded, their babies were more likely to weigh less on average than those of omnivorous mothers — 3441 g vs 3601 g — despite a mean gestation 5 days longer.

Prevalence rates of low birth weight (< 2500 g) in the two groups were 11.1% and 2.5%, respectively, and the prevalence of preeclampsia was 11.1% vs 2.6%. The mean birth weight of infants in the maternal vegan group was about 240 g lower than infants born to omnivorous mothers.

“The lower birth weight of around 240 g among vegans compared with omnivorous mothers in our study strengthens our observation that vegans may be at higher risk of giving birth to low-birth-weight infants. The observed effect size on birth weight is comparable to what is observed among daily smokers relative to nonsmokers in this cohort,“ Dr. Hedegaard and colleagues wrote. “Furthermore, the on-average 5-day longer gestation observed among vegans in our study would be indicative of reduced fetal growth rate rather than lower birth weight due to shorter gestation.”

These findings emerged from data on 66,738 pregnancies in the Danish National Birth Cohort, 1996-2002. A food frequency questionnaire characterized pregnant subjects as fish/poultry-vegetarians, lacto/ovo-vegetarians, vegans, or omnivores, based on their self-reporting in gestational week 30.

A total of 98.7% (n = 65,872) of participants were defined as omnivorous, while 1.0% (n = 666), 0.3% (n = 183), and 0.03% (n = 18) identified as fish/poultry vegetarians, lacto/ovo-vegetarians, or vegans, respectively.

Those following plant-based diets of all types were slightly older, more often parous, and less likely to smoke. This plant dietary group also had a somewhat lower prevalence of overweight and obesity (prepregnancy body mass index > 25 [kg/m^2]) and a higher prevalence of underweight (prepregnancy BMI < 18.5).

Total energy intake was modestly lower from plant-based diets, for a mean difference of 0.3-0.7 MJ (72-167 kcal) per day.

As for total protein intake, this was substantially lower for lacto/ovo-vegetarians and vegans: 13.3% and 10.4% of energy, respectively, compared with 15.4% in omnivores.

Dietary intake of micronutrients was also considerably lower among vegans, but after factoring in intake from dietary supplements, no major differences emerged.

Mean birth weight, birth length, length of gestation, and rate of low birth weight (< 2500 g) were similar among omnivorous, fish/poultry-, and lacto/ovo-vegetarians. The prevalence of gestational diabetes, preeclampsia, and cesarean section was similar across groups, but the prevalence of anemia was higher among fish/poultry- and lacto/ovo-vegetarians than omnivorous participants.

As for preeclampsia, previous research in larger numbers of vegans found no indication of hypertensive disorders during pregnancy. Some studies, however, have suggested a link between preeclampsia and low intake of protein, calcium, or vitamin D, but the evidence is inconclusive, and the mechanism is unclear.

The observed associations, however, do not translate to causality, the authors cautioned. “Future studies should put more emphasis on characterizing the diet among those adhering to vegan diets and other forms of plant-based diets during pregnancy,” they wrote. “That would allow for stronger assumptions on possible causality between any association observed with birth or pregnancy outcomes in such studies and strengthen the basis for dietary recommendations.”

This study was funded by the Danish Council for Independent Research. The Danish National Birth Cohort Study is supported by the March of Dimes Birth Defects Foundation, the Danish Heart Association, Danish Medical Research Council, Sygekassernes Helsefond, the Innovation Fund Denmark, and the Danish National Research Foundation. The authors had no conflicts of interest to declare.

Mothers on vegan diets during pregnancy may give birth to infants with lower mean birth weights than those of omnivorous mothers and may also have a greater risk of preeclampsia, a prospective study of Danish pregnant women suggests.

According to researchers led by Signe Hedegaard, MD, of the department of obstetrics and Gynecology at Rigshospitalet, Juliane Marie Center, University of Copenhagen, low protein intake may lie behind the observed association with birth weight. The report was published in Acta Obstetricia et Gynecologica Scandinavica.

While vegan-identifying mothers were very few in number, the authors conceded, their babies were more likely to weigh less on average than those of omnivorous mothers — 3441 g vs 3601 g — despite a mean gestation 5 days longer.

Prevalence rates of low birth weight (< 2500 g) in the two groups were 11.1% and 2.5%, respectively, and the prevalence of preeclampsia was 11.1% vs 2.6%. The mean birth weight of infants in the maternal vegan group was about 240 g lower than infants born to omnivorous mothers.

“The lower birth weight of around 240 g among vegans compared with omnivorous mothers in our study strengthens our observation that vegans may be at higher risk of giving birth to low-birth-weight infants. The observed effect size on birth weight is comparable to what is observed among daily smokers relative to nonsmokers in this cohort,“ Dr. Hedegaard and colleagues wrote. “Furthermore, the on-average 5-day longer gestation observed among vegans in our study would be indicative of reduced fetal growth rate rather than lower birth weight due to shorter gestation.”

These findings emerged from data on 66,738 pregnancies in the Danish National Birth Cohort, 1996-2002. A food frequency questionnaire characterized pregnant subjects as fish/poultry-vegetarians, lacto/ovo-vegetarians, vegans, or omnivores, based on their self-reporting in gestational week 30.

A total of 98.7% (n = 65,872) of participants were defined as omnivorous, while 1.0% (n = 666), 0.3% (n = 183), and 0.03% (n = 18) identified as fish/poultry vegetarians, lacto/ovo-vegetarians, or vegans, respectively.

Those following plant-based diets of all types were slightly older, more often parous, and less likely to smoke. This plant dietary group also had a somewhat lower prevalence of overweight and obesity (prepregnancy body mass index > 25 [kg/m^2]) and a higher prevalence of underweight (prepregnancy BMI < 18.5).

Total energy intake was modestly lower from plant-based diets, for a mean difference of 0.3-0.7 MJ (72-167 kcal) per day.

As for total protein intake, this was substantially lower for lacto/ovo-vegetarians and vegans: 13.3% and 10.4% of energy, respectively, compared with 15.4% in omnivores.

Dietary intake of micronutrients was also considerably lower among vegans, but after factoring in intake from dietary supplements, no major differences emerged.

Mean birth weight, birth length, length of gestation, and rate of low birth weight (< 2500 g) were similar among omnivorous, fish/poultry-, and lacto/ovo-vegetarians. The prevalence of gestational diabetes, preeclampsia, and cesarean section was similar across groups, but the prevalence of anemia was higher among fish/poultry- and lacto/ovo-vegetarians than omnivorous participants.

As for preeclampsia, previous research in larger numbers of vegans found no indication of hypertensive disorders during pregnancy. Some studies, however, have suggested a link between preeclampsia and low intake of protein, calcium, or vitamin D, but the evidence is inconclusive, and the mechanism is unclear.

The observed associations, however, do not translate to causality, the authors cautioned. “Future studies should put more emphasis on characterizing the diet among those adhering to vegan diets and other forms of plant-based diets during pregnancy,” they wrote. “That would allow for stronger assumptions on possible causality between any association observed with birth or pregnancy outcomes in such studies and strengthen the basis for dietary recommendations.”

This study was funded by the Danish Council for Independent Research. The Danish National Birth Cohort Study is supported by the March of Dimes Birth Defects Foundation, the Danish Heart Association, Danish Medical Research Council, Sygekassernes Helsefond, the Innovation Fund Denmark, and the Danish National Research Foundation. The authors had no conflicts of interest to declare.

Mothers on vegan diets during pregnancy may give birth to infants with lower mean birth weights than those of omnivorous mothers and may also have a greater risk of preeclampsia, a prospective study of Danish pregnant women suggests.

According to researchers led by Signe Hedegaard, MD, of the department of obstetrics and Gynecology at Rigshospitalet, Juliane Marie Center, University of Copenhagen, low protein intake may lie behind the observed association with birth weight. The report was published in Acta Obstetricia et Gynecologica Scandinavica.

While vegan-identifying mothers were very few in number, the authors conceded, their babies were more likely to weigh less on average than those of omnivorous mothers — 3441 g vs 3601 g — despite a mean gestation 5 days longer.

Prevalence rates of low birth weight (< 2500 g) in the two groups were 11.1% and 2.5%, respectively, and the prevalence of preeclampsia was 11.1% vs 2.6%. The mean birth weight of infants in the maternal vegan group was about 240 g lower than infants born to omnivorous mothers.

“The lower birth weight of around 240 g among vegans compared with omnivorous mothers in our study strengthens our observation that vegans may be at higher risk of giving birth to low-birth-weight infants. The observed effect size on birth weight is comparable to what is observed among daily smokers relative to nonsmokers in this cohort,“ Dr. Hedegaard and colleagues wrote. “Furthermore, the on-average 5-day longer gestation observed among vegans in our study would be indicative of reduced fetal growth rate rather than lower birth weight due to shorter gestation.”

These findings emerged from data on 66,738 pregnancies in the Danish National Birth Cohort, 1996-2002. A food frequency questionnaire characterized pregnant subjects as fish/poultry-vegetarians, lacto/ovo-vegetarians, vegans, or omnivores, based on their self-reporting in gestational week 30.

A total of 98.7% (n = 65,872) of participants were defined as omnivorous, while 1.0% (n = 666), 0.3% (n = 183), and 0.03% (n = 18) identified as fish/poultry vegetarians, lacto/ovo-vegetarians, or vegans, respectively.

Those following plant-based diets of all types were slightly older, more often parous, and less likely to smoke. This plant dietary group also had a somewhat lower prevalence of overweight and obesity (prepregnancy body mass index > 25 [kg/m^2]) and a higher prevalence of underweight (prepregnancy BMI < 18.5).

Total energy intake was modestly lower from plant-based diets, for a mean difference of 0.3-0.7 MJ (72-167 kcal) per day.

As for total protein intake, this was substantially lower for lacto/ovo-vegetarians and vegans: 13.3% and 10.4% of energy, respectively, compared with 15.4% in omnivores.

Dietary intake of micronutrients was also considerably lower among vegans, but after factoring in intake from dietary supplements, no major differences emerged.

Mean birth weight, birth length, length of gestation, and rate of low birth weight (< 2500 g) were similar among omnivorous, fish/poultry-, and lacto/ovo-vegetarians. The prevalence of gestational diabetes, preeclampsia, and cesarean section was similar across groups, but the prevalence of anemia was higher among fish/poultry- and lacto/ovo-vegetarians than omnivorous participants.

As for preeclampsia, previous research in larger numbers of vegans found no indication of hypertensive disorders during pregnancy. Some studies, however, have suggested a link between preeclampsia and low intake of protein, calcium, or vitamin D, but the evidence is inconclusive, and the mechanism is unclear.

The observed associations, however, do not translate to causality, the authors cautioned. “Future studies should put more emphasis on characterizing the diet among those adhering to vegan diets and other forms of plant-based diets during pregnancy,” they wrote. “That would allow for stronger assumptions on possible causality between any association observed with birth or pregnancy outcomes in such studies and strengthen the basis for dietary recommendations.”

This study was funded by the Danish Council for Independent Research. The Danish National Birth Cohort Study is supported by the March of Dimes Birth Defects Foundation, the Danish Heart Association, Danish Medical Research Council, Sygekassernes Helsefond, the Innovation Fund Denmark, and the Danish National Research Foundation. The authors had no conflicts of interest to declare.

Buprenorphine use, compared with methadone use, in pregnancy has been linked with a slightly lower risk of major congenital malformations in a new study of medications for opioid use disorder (OUD).

Elizabeth A. Suarez, PhD, MPH, with the Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women’s Hospital and Harvard Medical School in Boston, and colleagues published the findings in JAMA Internal Medicine.

The lower risk for buprenorphine was small (risk ratio, 0.82; 95% confidence interval [CI], 0.69-0.97), and methadone use should not be ruled out on that basis, the authors wrote. For some women, particularly those on stable treatment before pregnancy or women who do not respond well to buprenorphine, methadone may be the better choice, they explained.
 

Either Medication Better Than Not Treating

The authors noted that either medication “is strongly recommended over untreated OUD during pregnancy.”

JAMA Internal Medicine Deputy Editor Deborah Grady, MD, MPH, with the Department of Medicine, University of California, San Francisco, emphasized that recommendation in an editor’s note, highlighting that treatment for OUD is critical to prevent infections, overdose, and death in pregnant women as well as neonatal opioid withdrawal syndrome and fetal death.

She stressed that internists and other primary care physicians have a key role in ensuring pregnant women with OUD receive appropriate treatment.

Given the importance of the issue, she wrote, “we have taken the unusual step of publishing two accompanying invited commentaries.”

Two developments may help increase use of buprenorphine, the study authors wrote. One is a recent study showing lower risk of adverse neonatal outcomes when buprenorphine is used during pregnancy compared with methadone. Another is the removal last year of the prescribing waiver for buprenorphine.
 

Study Included Medicaid Data Over 18 Years

The population-based cohort study used data from publicly insured Medicaid beneficiaries from 2000 to 2018. Pregnancies with enrollment from 90 days before pregnancy through 1 month after delivery and first-trimester use of buprenorphine or methadone were included (n = 13,360). The data were linked with infants’ health data.

The study group included 9,514 pregnancies with first-trimester buprenorphine exposure and 3,846 with methadone exposure. The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone.

Major malformations were any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, oral clefts, and clubfoot.
 

Two Invited Commentaries Urge Caution in Interpretation

The two invited commentaries Dr. Grady mentioned in her editor’s note point both to the importance of the team’s findings and the need for better understanding of factors that may affect the choice of which OUD medication to use.

A commentary by Max Jordan Nguemeni Tiako, MD, MS, with the Department of Medicine, Brigham and Women’s Hospital, and colleagues, said that while the Suarez et al. data are important to share with patients, “the ultimate treatment decision must be the result of shared decision-making between a knowledgeable clinician and the patient, rather than promoting one medication over another.”

They urge putting the findings in context given the study population, which comprises a relatively stable group of women with OUD, most of whom were taking OUD medications before they got pregnant. The study sample excludes a substantial number of women who are chronically underinsured or uninsured, Dr. Tiako’s team wrote, because those included were enrolled in Medicaid for 3 consecutive months before pregnancy.

“We urge caution when extrapolating these findings to newly pregnant individuals with untreated OUD,” they wrote.
 

Both Medications are Safe

Cara Poland, MD, MEd, with the Henry Ford Health + Michigan State University Health Sciences in Grand Rapids, and coauthors, added in another commentary that Suarez et al. didn’t include a comparison between the population-level congenital defect rate and the defect rate for people using medications for OUD in pregnancy.

That comparison, they wrote, would have better illustrated the safety of medications for OUD “instead of simply comparing two medications with long-standing safety data.”

When a clinician starts a woman on medication for OUD in pregnancy, it’s important to understand several factors, including individual access to and comfort with different treatment approaches, they noted. It’s also important to weigh whether changing medications is worth the potential drawbacks of disrupting their well-managed care.

They wrote that the paper by Suarez et al. does not make the case for switching medications based on their findings.

Internists, they added, are ideal experts to explain risk of fetal abnormalities in the wider context of supporting engagement with continuous medication for OUD.

“In the absence of other concerns, switching medications (methadone to buprenorphine) or — worse — discontinuing [medication for] OUD because of this study runs counter to the substantial evidence regarding the safety of these medications during pregnancy,” Dr. Poland’s team wrote. “No treatment is without risk in pregnancy.”

This study was supported by the National Institute on Drug Abuse. In the Suarez et al. study, coauthors Dr. Hernández-Díaz, Dr. Gray, Dr. Connery, Dr. Zhu, and Dr. Huybrechts reported grants, personal fees and consulting payments from several pharmaceutical companies. Dr. Grady reports no relevant financial relationships in her editor’s note. No relevant financial relationships were reported by authors of the Tiako et al. commentary.

Regarding the commentary by Poland et al., grants were reported from the Michigan Health Endowment Fund, the Michigan Department of Health and Human Services, the National Institute on Drug Abuse and Blue Cross Blue Shield of Michigan outside the submitted work. No other disclosures were reported.

Buprenorphine use, compared with methadone use, in pregnancy has been linked with a slightly lower risk of major congenital malformations in a new study of medications for opioid use disorder (OUD).

Elizabeth A. Suarez, PhD, MPH, with the Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women’s Hospital and Harvard Medical School in Boston, and colleagues published the findings in JAMA Internal Medicine.

The lower risk for buprenorphine was small (risk ratio, 0.82; 95% confidence interval [CI], 0.69-0.97), and methadone use should not be ruled out on that basis, the authors wrote. For some women, particularly those on stable treatment before pregnancy or women who do not respond well to buprenorphine, methadone may be the better choice, they explained.
 

Either Medication Better Than Not Treating

The authors noted that either medication “is strongly recommended over untreated OUD during pregnancy.”

JAMA Internal Medicine Deputy Editor Deborah Grady, MD, MPH, with the Department of Medicine, University of California, San Francisco, emphasized that recommendation in an editor’s note, highlighting that treatment for OUD is critical to prevent infections, overdose, and death in pregnant women as well as neonatal opioid withdrawal syndrome and fetal death.

She stressed that internists and other primary care physicians have a key role in ensuring pregnant women with OUD receive appropriate treatment.

Given the importance of the issue, she wrote, “we have taken the unusual step of publishing two accompanying invited commentaries.”

Two developments may help increase use of buprenorphine, the study authors wrote. One is a recent study showing lower risk of adverse neonatal outcomes when buprenorphine is used during pregnancy compared with methadone. Another is the removal last year of the prescribing waiver for buprenorphine.
 

Study Included Medicaid Data Over 18 Years

The population-based cohort study used data from publicly insured Medicaid beneficiaries from 2000 to 2018. Pregnancies with enrollment from 90 days before pregnancy through 1 month after delivery and first-trimester use of buprenorphine or methadone were included (n = 13,360). The data were linked with infants’ health data.

The study group included 9,514 pregnancies with first-trimester buprenorphine exposure and 3,846 with methadone exposure. The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone.

Major malformations were any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, oral clefts, and clubfoot.
 

Two Invited Commentaries Urge Caution in Interpretation

The two invited commentaries Dr. Grady mentioned in her editor’s note point both to the importance of the team’s findings and the need for better understanding of factors that may affect the choice of which OUD medication to use.

A commentary by Max Jordan Nguemeni Tiako, MD, MS, with the Department of Medicine, Brigham and Women’s Hospital, and colleagues, said that while the Suarez et al. data are important to share with patients, “the ultimate treatment decision must be the result of shared decision-making between a knowledgeable clinician and the patient, rather than promoting one medication over another.”

They urge putting the findings in context given the study population, which comprises a relatively stable group of women with OUD, most of whom were taking OUD medications before they got pregnant. The study sample excludes a substantial number of women who are chronically underinsured or uninsured, Dr. Tiako’s team wrote, because those included were enrolled in Medicaid for 3 consecutive months before pregnancy.

“We urge caution when extrapolating these findings to newly pregnant individuals with untreated OUD,” they wrote.
 

Both Medications are Safe

Cara Poland, MD, MEd, with the Henry Ford Health + Michigan State University Health Sciences in Grand Rapids, and coauthors, added in another commentary that Suarez et al. didn’t include a comparison between the population-level congenital defect rate and the defect rate for people using medications for OUD in pregnancy.

That comparison, they wrote, would have better illustrated the safety of medications for OUD “instead of simply comparing two medications with long-standing safety data.”

When a clinician starts a woman on medication for OUD in pregnancy, it’s important to understand several factors, including individual access to and comfort with different treatment approaches, they noted. It’s also important to weigh whether changing medications is worth the potential drawbacks of disrupting their well-managed care.

They wrote that the paper by Suarez et al. does not make the case for switching medications based on their findings.

Internists, they added, are ideal experts to explain risk of fetal abnormalities in the wider context of supporting engagement with continuous medication for OUD.

“In the absence of other concerns, switching medications (methadone to buprenorphine) or — worse — discontinuing [medication for] OUD because of this study runs counter to the substantial evidence regarding the safety of these medications during pregnancy,” Dr. Poland’s team wrote. “No treatment is without risk in pregnancy.”

This study was supported by the National Institute on Drug Abuse. In the Suarez et al. study, coauthors Dr. Hernández-Díaz, Dr. Gray, Dr. Connery, Dr. Zhu, and Dr. Huybrechts reported grants, personal fees and consulting payments from several pharmaceutical companies. Dr. Grady reports no relevant financial relationships in her editor’s note. No relevant financial relationships were reported by authors of the Tiako et al. commentary.

Regarding the commentary by Poland et al., grants were reported from the Michigan Health Endowment Fund, the Michigan Department of Health and Human Services, the National Institute on Drug Abuse and Blue Cross Blue Shield of Michigan outside the submitted work. No other disclosures were reported.

Buprenorphine use, compared with methadone use, in pregnancy has been linked with a slightly lower risk of major congenital malformations in a new study of medications for opioid use disorder (OUD).

Elizabeth A. Suarez, PhD, MPH, with the Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women’s Hospital and Harvard Medical School in Boston, and colleagues published the findings in JAMA Internal Medicine.

The lower risk for buprenorphine was small (risk ratio, 0.82; 95% confidence interval [CI], 0.69-0.97), and methadone use should not be ruled out on that basis, the authors wrote. For some women, particularly those on stable treatment before pregnancy or women who do not respond well to buprenorphine, methadone may be the better choice, they explained.
 

Either Medication Better Than Not Treating

The authors noted that either medication “is strongly recommended over untreated OUD during pregnancy.”

JAMA Internal Medicine Deputy Editor Deborah Grady, MD, MPH, with the Department of Medicine, University of California, San Francisco, emphasized that recommendation in an editor’s note, highlighting that treatment for OUD is critical to prevent infections, overdose, and death in pregnant women as well as neonatal opioid withdrawal syndrome and fetal death.

She stressed that internists and other primary care physicians have a key role in ensuring pregnant women with OUD receive appropriate treatment.

Given the importance of the issue, she wrote, “we have taken the unusual step of publishing two accompanying invited commentaries.”

Two developments may help increase use of buprenorphine, the study authors wrote. One is a recent study showing lower risk of adverse neonatal outcomes when buprenorphine is used during pregnancy compared with methadone. Another is the removal last year of the prescribing waiver for buprenorphine.
 

Study Included Medicaid Data Over 18 Years

The population-based cohort study used data from publicly insured Medicaid beneficiaries from 2000 to 2018. Pregnancies with enrollment from 90 days before pregnancy through 1 month after delivery and first-trimester use of buprenorphine or methadone were included (n = 13,360). The data were linked with infants’ health data.

The study group included 9,514 pregnancies with first-trimester buprenorphine exposure and 3,846 with methadone exposure. The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone.

Major malformations were any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, oral clefts, and clubfoot.
 

Two Invited Commentaries Urge Caution in Interpretation

The two invited commentaries Dr. Grady mentioned in her editor’s note point both to the importance of the team’s findings and the need for better understanding of factors that may affect the choice of which OUD medication to use.

A commentary by Max Jordan Nguemeni Tiako, MD, MS, with the Department of Medicine, Brigham and Women’s Hospital, and colleagues, said that while the Suarez et al. data are important to share with patients, “the ultimate treatment decision must be the result of shared decision-making between a knowledgeable clinician and the patient, rather than promoting one medication over another.”

They urge putting the findings in context given the study population, which comprises a relatively stable group of women with OUD, most of whom were taking OUD medications before they got pregnant. The study sample excludes a substantial number of women who are chronically underinsured or uninsured, Dr. Tiako’s team wrote, because those included were enrolled in Medicaid for 3 consecutive months before pregnancy.

“We urge caution when extrapolating these findings to newly pregnant individuals with untreated OUD,” they wrote.
 

Both Medications are Safe

Cara Poland, MD, MEd, with the Henry Ford Health + Michigan State University Health Sciences in Grand Rapids, and coauthors, added in another commentary that Suarez et al. didn’t include a comparison between the population-level congenital defect rate and the defect rate for people using medications for OUD in pregnancy.

That comparison, they wrote, would have better illustrated the safety of medications for OUD “instead of simply comparing two medications with long-standing safety data.”

When a clinician starts a woman on medication for OUD in pregnancy, it’s important to understand several factors, including individual access to and comfort with different treatment approaches, they noted. It’s also important to weigh whether changing medications is worth the potential drawbacks of disrupting their well-managed care.

They wrote that the paper by Suarez et al. does not make the case for switching medications based on their findings.

Internists, they added, are ideal experts to explain risk of fetal abnormalities in the wider context of supporting engagement with continuous medication for OUD.

“In the absence of other concerns, switching medications (methadone to buprenorphine) or — worse — discontinuing [medication for] OUD because of this study runs counter to the substantial evidence regarding the safety of these medications during pregnancy,” Dr. Poland’s team wrote. “No treatment is without risk in pregnancy.”

This study was supported by the National Institute on Drug Abuse. In the Suarez et al. study, coauthors Dr. Hernández-Díaz, Dr. Gray, Dr. Connery, Dr. Zhu, and Dr. Huybrechts reported grants, personal fees and consulting payments from several pharmaceutical companies. Dr. Grady reports no relevant financial relationships in her editor’s note. No relevant financial relationships were reported by authors of the Tiako et al. commentary.

Regarding the commentary by Poland et al., grants were reported from the Michigan Health Endowment Fund, the Michigan Department of Health and Human Services, the National Institute on Drug Abuse and Blue Cross Blue Shield of Michigan outside the submitted work. No other disclosures were reported.

TOPLINE:

Previous gestational diabetes mellitus (GDM) nearly doubles future chronic kidney disease (CKD) risk, irrespective of subsequent diabetes and hypertension, a study showed.

METHODOLOGY:

• A nationwide, cohort study was based on data from the Danish Medical Birth Register and included 697,622 women who gave birth between 1997 and 2018.
• Of all study participants, 3.4% reported GDM in at least one pregnancy, and 12.8% of women with GDM received insulin, a proxy for a more severe metabolic dysfunction.
• The women were followed up for a median of 11.9 years.
• Researchers studied CKD and acute kidney disease as the outcomes of interest, the mediating effects of subsequent diabetes and hypertension on future CKD, and how GDM severity affected later risk for kidney disease.

TAKEAWAY:

• Women with GDM showed significantly higher CKD risk than those without GDM (adjusted hazard ratio [aHR], 1.92; 95% CI, 1.67-2.21).
• Women who received insulin during pregnancy due to severe metabolic dysfunction but did not develop subsequent diabetes had a proportionally higher risk for CKD (aHR, 2.35; 95% CI, 1.39-3.97).
• Women with GDM who went on to develop diabetes or hypertension faced even higher risks for CKD, suggesting that preventing diabetes and hypertension after GDM may reduce the development of CKD.
• GDM did not affect the risk for acute kidney disease (aHR, 1.08; 95% CI, 0.90-1.29).

IN PRACTICE:

“Women with severe metabolic dysfunction during pregnancy constitute a high-risk group regarding future CKD,” the authors wrote. “The significantly elevated CKD risk was observed from 2 years after pregnancy and beyond.”

SOURCE:

The study, with first author Maria Hornstrup Christensen, of Odense University Hospital, Odense, Denmark, was published online on December 15 in Diabetes Care.

LIMITATIONS:

GDM may be underdiagnosed, and undiagnosed diabetes may be misclassified as GDM. The proxies of GDM and insulin treatment may not have captured the increasing severity of metabolic dysfunction. The prevalence of insulin treatment was lower than expected, perhaps due to the practice of providing a patient’s first insulin pen without a prescription and perhaps not recording it in a patient’s health record.

DISCLOSURES:

This work received financial support from the University of Southern Denmark, the Region of Southern Denmark, and the Danish Diabetes Academy, which is funded by the Novo Nordisk Foundation. The authors declared no conflicts of interest.
 

A version of this article appeared on Medscape.com.

TOPLINE:

Previous gestational diabetes mellitus (GDM) nearly doubles future chronic kidney disease (CKD) risk, irrespective of subsequent diabetes and hypertension, a study showed.

METHODOLOGY:

• A nationwide, cohort study was based on data from the Danish Medical Birth Register and included 697,622 women who gave birth between 1997 and 2018.
• Of all study participants, 3.4% reported GDM in at least one pregnancy, and 12.8% of women with GDM received insulin, a proxy for a more severe metabolic dysfunction.
• The women were followed up for a median of 11.9 years.
• Researchers studied CKD and acute kidney disease as the outcomes of interest, the mediating effects of subsequent diabetes and hypertension on future CKD, and how GDM severity affected later risk for kidney disease.

TAKEAWAY:

• Women with GDM showed significantly higher CKD risk than those without GDM (adjusted hazard ratio [aHR], 1.92; 95% CI, 1.67-2.21).
• Women who received insulin during pregnancy due to severe metabolic dysfunction but did not develop subsequent diabetes had a proportionally higher risk for CKD (aHR, 2.35; 95% CI, 1.39-3.97).
• Women with GDM who went on to develop diabetes or hypertension faced even higher risks for CKD, suggesting that preventing diabetes and hypertension after GDM may reduce the development of CKD.
• GDM did not affect the risk for acute kidney disease (aHR, 1.08; 95% CI, 0.90-1.29).

IN PRACTICE:

“Women with severe metabolic dysfunction during pregnancy constitute a high-risk group regarding future CKD,” the authors wrote. “The significantly elevated CKD risk was observed from 2 years after pregnancy and beyond.”

SOURCE:

The study, with first author Maria Hornstrup Christensen, of Odense University Hospital, Odense, Denmark, was published online on December 15 in Diabetes Care.

LIMITATIONS:

GDM may be underdiagnosed, and undiagnosed diabetes may be misclassified as GDM. The proxies of GDM and insulin treatment may not have captured the increasing severity of metabolic dysfunction. The prevalence of insulin treatment was lower than expected, perhaps due to the practice of providing a patient’s first insulin pen without a prescription and perhaps not recording it in a patient’s health record.

DISCLOSURES:

This work received financial support from the University of Southern Denmark, the Region of Southern Denmark, and the Danish Diabetes Academy, which is funded by the Novo Nordisk Foundation. The authors declared no conflicts of interest.
 

A version of this article appeared on Medscape.com.

TOPLINE:

Previous gestational diabetes mellitus (GDM) nearly doubles future chronic kidney disease (CKD) risk, irrespective of subsequent diabetes and hypertension, a study showed.

METHODOLOGY:

• A nationwide, cohort study was based on data from the Danish Medical Birth Register and included 697,622 women who gave birth between 1997 and 2018.
• Of all study participants, 3.4% reported GDM in at least one pregnancy, and 12.8% of women with GDM received insulin, a proxy for a more severe metabolic dysfunction.
• The women were followed up for a median of 11.9 years.
• Researchers studied CKD and acute kidney disease as the outcomes of interest, the mediating effects of subsequent diabetes and hypertension on future CKD, and how GDM severity affected later risk for kidney disease.

TAKEAWAY:

• Women with GDM showed significantly higher CKD risk than those without GDM (adjusted hazard ratio [aHR], 1.92; 95% CI, 1.67-2.21).
• Women who received insulin during pregnancy due to severe metabolic dysfunction but did not develop subsequent diabetes had a proportionally higher risk for CKD (aHR, 2.35; 95% CI, 1.39-3.97).
• Women with GDM who went on to develop diabetes or hypertension faced even higher risks for CKD, suggesting that preventing diabetes and hypertension after GDM may reduce the development of CKD.
• GDM did not affect the risk for acute kidney disease (aHR, 1.08; 95% CI, 0.90-1.29).

IN PRACTICE:

“Women with severe metabolic dysfunction during pregnancy constitute a high-risk group regarding future CKD,” the authors wrote. “The significantly elevated CKD risk was observed from 2 years after pregnancy and beyond.”

SOURCE:

The study, with first author Maria Hornstrup Christensen, of Odense University Hospital, Odense, Denmark, was published online on December 15 in Diabetes Care.

LIMITATIONS:

GDM may be underdiagnosed, and undiagnosed diabetes may be misclassified as GDM. The proxies of GDM and insulin treatment may not have captured the increasing severity of metabolic dysfunction. The prevalence of insulin treatment was lower than expected, perhaps due to the practice of providing a patient’s first insulin pen without a prescription and perhaps not recording it in a patient’s health record.

DISCLOSURES:

This work received financial support from the University of Southern Denmark, the Region of Southern Denmark, and the Danish Diabetes Academy, which is funded by the Novo Nordisk Foundation. The authors declared no conflicts of interest.
 

A version of this article appeared on Medscape.com.

Women with autoimmune disease are more likely to have perinatal depression (PND), according to findings from a new study that also suggested the reverse relationship is true: Women with a history of PND have a higher risk of developing autoimmune disease.

The research, published online on January 9, 2024, in Molecular Psychiatry, was led by Emma Bränn, PhD, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.

The researchers used data from the Swedish Medical Birth Register and identified all women who had given birth in Sweden between 2001 and 2013. Out of the group of approximately 815,000 women and 1.3 million pregnancies, just more than 55,000 women had been diagnosed with depression during their pregnancy or within a year after delivery.

The researchers then compared the incidence of 41 autoimmune diseases in women who had and did not have PND. They controlled for factors including genetic makeup and childhood environment.

Results indicated that women with autoimmune disease were 30% more likely to have PND (odds ratio, 1.30; 95% CI, 1.25-1.35). Conversely, women with PND were 30% more likely than women with no PND to develop an autoimmune disease (hazard ratio, 1.30; 95% CI, 1.25-1.36).

A sibling comparison helped confirm the results by controlling for some shared genetic and early life environmental factors related to the household in which sisters grew up.
 

Potential Shared Biological Mechanisms

The association was independent of psychiatric comorbidities, suggesting there may be shared biological mechanisms.

Dr. Bränn told this news organization that the research team wanted to do the study because previous research has shown involvement of the immune system in depression, with similarities in both the symptoms of immune system–activated diseases and depression and the molecular pathways activated by the immune system.

“Adding on top of the tremendous changes in the immune system that we see in the body of the woman during the perinatal period, we hypothesized that autoimmune diseases could be associated to perinatal depression,” she said. “This had also been shown in some previous literature but not to the extent as what we have investigated in this paper.”

She said their results help make a case for counseling women at several points in healthcare interactions — before and after conception and childbirth — and in rheumatology visits to inform women with autoimmune diseases who are contemplating motherhood of the association with developing PND. The results may also demonstrate a need for monitoring women in these groups for depression or autoimmune disease.

Fred Miller, MD, PhD, retired Scientist Emeritus of the Environmental Autoimmunity Group at the National Institute of Environmental Health Sciences, who was not part of the study, said the results seem plausible as they build on early work that demonstrated selected associations between autoimmune conditions and mental illness.

“These associations may be the result of shared genetic and environmental risk factors, including stress, hormonal changes, medications, and the proinflammatory states that can lead to both,” he said.

The novelty, he said, is in the relatively strong associations of PND with autoimmune disease overall and with specific autoimmune diseases.
 

Strong Link Found With Multiple Sclerosis (MS)

According to the paper, a significant positive bidirectional link was found for autoimmune thyroid disease, psoriasis, MS, ulcerative colitis, and celiac disease.

Researchers found a particularly strong association — double the risk in both directions — between PND and MS.

Dr. Miller said though it is unclear from this study why the association of PND with MS was stronger than with other autoimmune diseases, people with MS are known to be at a high risk for depression in general. That may come from greater shared genetic and environmental risk factors, he added.

Additionally, MS is one of the more common autoimmune diseases, he noted, so the population is larger for study.

He said he was surprised the researchers didn’t investigate medication use because medications used in depression have immunologic effects and medications used in autoimmune diseases could have effects on mental conditions.

The study has implications for clinicians in a wide variety of specialties, Dr. Miller noted.

“It suggests that caregivers be more alert to the signs of developing autoimmune disease in women with perinatal depression and to the signs of developing perinatal depression in those with autoimmune disease,” Dr. Miller said, “so that appropriate screening, diagnostics, and interventions may be undertaken.”

The researchers say they will continue to examine the long-term effects of depression during pregnancy and in the year after childbirth.

“Depression during this sensitive period can have serious consequences for both the mother and the baby,” Dr. Bränn said. “We hope that our results will help decision-makers to steer funding toward maternal healthcare so that more women can get help and support in time.”

The study was financed by Karolinska Institute, Forte (the Swedish Research Council for Health, Working Life and Welfare), the Swedish Research Council, and the Icelandic Research Fund.

The researchers and Dr. Miller reported no relevant financial relationships.

A version of this article appeared on Medscape.com.

Women with autoimmune disease are more likely to have perinatal depression (PND), according to findings from a new study that also suggested the reverse relationship is true: Women with a history of PND have a higher risk of developing autoimmune disease.

The research, published online on January 9, 2024, in Molecular Psychiatry, was led by Emma Bränn, PhD, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.

The researchers used data from the Swedish Medical Birth Register and identified all women who had given birth in Sweden between 2001 and 2013. Out of the group of approximately 815,000 women and 1.3 million pregnancies, just more than 55,000 women had been diagnosed with depression during their pregnancy or within a year after delivery.

The researchers then compared the incidence of 41 autoimmune diseases in women who had and did not have PND. They controlled for factors including genetic makeup and childhood environment.

Results indicated that women with autoimmune disease were 30% more likely to have PND (odds ratio, 1.30; 95% CI, 1.25-1.35). Conversely, women with PND were 30% more likely than women with no PND to develop an autoimmune disease (hazard ratio, 1.30; 95% CI, 1.25-1.36).

A sibling comparison helped confirm the results by controlling for some shared genetic and early life environmental factors related to the household in which sisters grew up.
 

Potential Shared Biological Mechanisms

The association was independent of psychiatric comorbidities, suggesting there may be shared biological mechanisms.

Dr. Bränn told this news organization that the research team wanted to do the study because previous research has shown involvement of the immune system in depression, with similarities in both the symptoms of immune system–activated diseases and depression and the molecular pathways activated by the immune system.

“Adding on top of the tremendous changes in the immune system that we see in the body of the woman during the perinatal period, we hypothesized that autoimmune diseases could be associated to perinatal depression,” she said. “This had also been shown in some previous literature but not to the extent as what we have investigated in this paper.”

She said their results help make a case for counseling women at several points in healthcare interactions — before and after conception and childbirth — and in rheumatology visits to inform women with autoimmune diseases who are contemplating motherhood of the association with developing PND. The results may also demonstrate a need for monitoring women in these groups for depression or autoimmune disease.

Fred Miller, MD, PhD, retired Scientist Emeritus of the Environmental Autoimmunity Group at the National Institute of Environmental Health Sciences, who was not part of the study, said the results seem plausible as they build on early work that demonstrated selected associations between autoimmune conditions and mental illness.

“These associations may be the result of shared genetic and environmental risk factors, including stress, hormonal changes, medications, and the proinflammatory states that can lead to both,” he said.

The novelty, he said, is in the relatively strong associations of PND with autoimmune disease overall and with specific autoimmune diseases.
 

Strong Link Found With Multiple Sclerosis (MS)

According to the paper, a significant positive bidirectional link was found for autoimmune thyroid disease, psoriasis, MS, ulcerative colitis, and celiac disease.

Researchers found a particularly strong association — double the risk in both directions — between PND and MS.

Dr. Miller said though it is unclear from this study why the association of PND with MS was stronger than with other autoimmune diseases, people with MS are known to be at a high risk for depression in general. That may come from greater shared genetic and environmental risk factors, he added.

Additionally, MS is one of the more common autoimmune diseases, he noted, so the population is larger for study.

He said he was surprised the researchers didn’t investigate medication use because medications used in depression have immunologic effects and medications used in autoimmune diseases could have effects on mental conditions.

The study has implications for clinicians in a wide variety of specialties, Dr. Miller noted.

“It suggests that caregivers be more alert to the signs of developing autoimmune disease in women with perinatal depression and to the signs of developing perinatal depression in those with autoimmune disease,” Dr. Miller said, “so that appropriate screening, diagnostics, and interventions may be undertaken.”

The researchers say they will continue to examine the long-term effects of depression during pregnancy and in the year after childbirth.

“Depression during this sensitive period can have serious consequences for both the mother and the baby,” Dr. Bränn said. “We hope that our results will help decision-makers to steer funding toward maternal healthcare so that more women can get help and support in time.”

The study was financed by Karolinska Institute, Forte (the Swedish Research Council for Health, Working Life and Welfare), the Swedish Research Council, and the Icelandic Research Fund.

The researchers and Dr. Miller reported no relevant financial relationships.

A version of this article appeared on Medscape.com.

Women with autoimmune disease are more likely to have perinatal depression (PND), according to findings from a new study that also suggested the reverse relationship is true: Women with a history of PND have a higher risk of developing autoimmune disease.

The research, published online on January 9, 2024, in Molecular Psychiatry, was led by Emma Bränn, PhD, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.

The researchers used data from the Swedish Medical Birth Register and identified all women who had given birth in Sweden between 2001 and 2013. Out of the group of approximately 815,000 women and 1.3 million pregnancies, just more than 55,000 women had been diagnosed with depression during their pregnancy or within a year after delivery.

The researchers then compared the incidence of 41 autoimmune diseases in women who had and did not have PND. They controlled for factors including genetic makeup and childhood environment.

Results indicated that women with autoimmune disease were 30% more likely to have PND (odds ratio, 1.30; 95% CI, 1.25-1.35). Conversely, women with PND were 30% more likely than women with no PND to develop an autoimmune disease (hazard ratio, 1.30; 95% CI, 1.25-1.36).

A sibling comparison helped confirm the results by controlling for some shared genetic and early life environmental factors related to the household in which sisters grew up.
 

Potential Shared Biological Mechanisms

The association was independent of psychiatric comorbidities, suggesting there may be shared biological mechanisms.

Dr. Bränn told this news organization that the research team wanted to do the study because previous research has shown involvement of the immune system in depression, with similarities in both the symptoms of immune system–activated diseases and depression and the molecular pathways activated by the immune system.

“Adding on top of the tremendous changes in the immune system that we see in the body of the woman during the perinatal period, we hypothesized that autoimmune diseases could be associated to perinatal depression,” she said. “This had also been shown in some previous literature but not to the extent as what we have investigated in this paper.”

She said their results help make a case for counseling women at several points in healthcare interactions — before and after conception and childbirth — and in rheumatology visits to inform women with autoimmune diseases who are contemplating motherhood of the association with developing PND. The results may also demonstrate a need for monitoring women in these groups for depression or autoimmune disease.

Fred Miller, MD, PhD, retired Scientist Emeritus of the Environmental Autoimmunity Group at the National Institute of Environmental Health Sciences, who was not part of the study, said the results seem plausible as they build on early work that demonstrated selected associations between autoimmune conditions and mental illness.

“These associations may be the result of shared genetic and environmental risk factors, including stress, hormonal changes, medications, and the proinflammatory states that can lead to both,” he said.

The novelty, he said, is in the relatively strong associations of PND with autoimmune disease overall and with specific autoimmune diseases.
 

Strong Link Found With Multiple Sclerosis (MS)

According to the paper, a significant positive bidirectional link was found for autoimmune thyroid disease, psoriasis, MS, ulcerative colitis, and celiac disease.

Researchers found a particularly strong association — double the risk in both directions — between PND and MS.

Dr. Miller said though it is unclear from this study why the association of PND with MS was stronger than with other autoimmune diseases, people with MS are known to be at a high risk for depression in general. That may come from greater shared genetic and environmental risk factors, he added.

Additionally, MS is one of the more common autoimmune diseases, he noted, so the population is larger for study.

He said he was surprised the researchers didn’t investigate medication use because medications used in depression have immunologic effects and medications used in autoimmune diseases could have effects on mental conditions.

The study has implications for clinicians in a wide variety of specialties, Dr. Miller noted.

“It suggests that caregivers be more alert to the signs of developing autoimmune disease in women with perinatal depression and to the signs of developing perinatal depression in those with autoimmune disease,” Dr. Miller said, “so that appropriate screening, diagnostics, and interventions may be undertaken.”

The researchers say they will continue to examine the long-term effects of depression during pregnancy and in the year after childbirth.

“Depression during this sensitive period can have serious consequences for both the mother and the baby,” Dr. Bränn said. “We hope that our results will help decision-makers to steer funding toward maternal healthcare so that more women can get help and support in time.”

The study was financed by Karolinska Institute, Forte (the Swedish Research Council for Health, Working Life and Welfare), the Swedish Research Council, and the Icelandic Research Fund.

The researchers and Dr. Miller reported no relevant financial relationships.

A version of this article appeared on Medscape.com.

FAIRFAX, VIRGINIA — Pharmacologic treatment of gestational diabetes mellitus (GDM) remains challenged by overall poor trial quality, clinical practice guidelines that offer differing advice, and a limited ability to predict individual risk and treatment response, but researchers at the biennial meeting of the Diabetes in Pregnancy Study Group of North America expressed hope for more clarity in the near future and the ability to someday individualize treatment to account for what is increasingly viewed as a heterogeneous condition.

Until studies in 2015 and 2018 cast doubt on glyburide, “we used to have 80% [of our GDM patients] on glyburide, and 20% on insulin,” Maisa Feghali, MD, of the University of Pittsburgh, said during a discussion period. “Now we have 95% on insulin and 5% on oral hypoglycemics. I rely on insulin because I don’t have a better option, and I rely on research efforts [underway to provide better options]” in the future.

The American College of Obstetricians and Gynecologists recommends insulin as the preferred first-line pharmacologic therapy for GDM when pharmacologic therapy is needed, with metformin as an option when patients decline or cannot safely use insulin. Glyburide, ACOG said in its 2018 practice bulletin on GDM (Obstet Gynecol. 2018;131[2]:e49-64), should not be recommended as a first-line pharmacologic therapy.

The Society of Maternal-Fetal Medicine, on the other hand, has accepted metformin as a “reasonable and safe” first-line alternative to insulin — while recognizing that half of women will still require insulin to achieve glycemic control — and does not rule out consideration of glyburide. In its 2018 statement on the pharmacologic treatment of GDM, the society said that the evidence of benefit of one oral agent over another remains limited.  

“When you have dueling guidelines, it means the data are not that clear,” George Saade, MD, professor and chair of obstetrics and gynecology at the Eastern Virginia School of Medicine, Norfolk, said in a presentation on GDM. An upcoming $12 million multicenter study to be led by the Ohio State University College of Medicine — coined the DECIDE trial — should provide clarity, he said.

The trial, funded by the Patient-Centered Outcomes Research Institute, which funds comparative clinical effectiveness research designed to be broadly applicable to practice, will enroll and randomize over 1500 pregnant individuals with GDM to either oral metformin or insulin and will follow mothers and children until 2 years after delivery.

The study’s primary and secondary hypotheses, respectively, are that metformin is not inferior to insulin in reducing a composite adverse neonatal outcome (large for gestational age, neonatal hypoglycemia and/or hyperbilirubemia) and that metformin does not result in increased child body mass index at 2 years, compared with insulin. It will also look at patient-reported factors associated with metformin use compared to insulin use — factors that “are important ... to enable clinical implementation of study findings,” said Dr. Saade, who played a role in designing the study over the past several years.

The study will take a pragmatic, real-world approach by ensuring racial and ethnic, socioeconomic, urban and rural, and geographic diversity at both large academic and community-based sites across the United States.

The trial, to be led by Mark Landon, MD, and Kartik Venkatesh, MD, PhD, of Ohio State University, will be the first large trial in the United States to both directly compare the ability of oral hypoglycemics and insulin to prevent GDM-associated pregnancy complications, and to follow children for 2 years, Dr. Saade said. “Prior research was either outside the United States, not randomized, not adequately powered, or had no long-term child follow-up,” he added after the meeting.
 

The State Of Knowledge About Oral Hypoglycemics

The trial was envisioned several years ago as a three-arm comparative trial including the sulfonylurea glyburide, but data published in recent years has increasingly “not favored” glyburide, and many providers “have stopped using it,” Dr. Saade said during and after the meeting. At this point, “it would not be useful to include it” in a pragmatic trial, he said.

Glyburide became the number one agent after a seminal trial published in 2000 (N Engl J Med. 2000;343:1134-8) showed equivalent glycemic control in about 400 women with GDM who were randomized to receive insulin or glyburide. While the trial was not powered to evaluate other outcomes, there were no significant differences in neonatal complications.

In 2015, a large retrospective population-based study (JAMA Pediatr. 2015;169[5]:452-8) of more than 9,000 women with GDM showed higher risks of neonatal intensive care admission, neonatal hypoglycemia, and large-for-gestational age with glyburide compared with insulin. “It prompted a pause in thinking,” Dr. Saade recalled at the DPSG meeting. After that, several meta-analyses/systematic reviews compared the two treatments, showing varying and sometimes conflicting degrees of difference in neonatal outcomes.

In 2018, a French noninferiority randomized controlled trial (JAMA 2018;319[17]:1773-80) did not show that glyburide is not inferior to insulin in the prevention of perinatal outcomes (macrosomia, neonatal hypoglycemia, and hyperbilirubinemia). “If you add this trial to the systematic reviews, it would probably would shift more in favor of insulin,” Dr. Saade said, noting that the trial’s supplementary data included a higher rate of maternal hypoglycemia with glyburide. “I feel personally now, with all the data, that glyburide is inferior to insulin.”

A 2021 network meta-analysis (BMC Endocr Disord. 2021;21:199) that looked at glycemic control and neonatal outcomes in GDM treated with glyburide, metformin, or insulin, also offers valuable insight, Dr. Saade said. The meta-analysis used a Bayesian framework and presents results as a ranking estimated probability of a treatment being the best or worst — or in between — for different outcomes (glycemic control and neonatal outcomes), which “is one of the best ways to look at data these days,” he said.

“It tells us how likely [it is for one agent] to be better than others. Will it work most of the time? More than 60% of the time?” Dr. Saade explained. For example, the analysis “tell us that for large for gestational age, glyburide has a 94% chance of being the worst, metformin has an 80% change of being the best, and insulin a 76% chance of being in between.”

Overall, the 2021 analysis suggests that “glyburide is the most likely to be worst in most outcomes and that there is equipoise between metformin and insulin,” he said.

Meta-analyses of pharmacologic treatment of GDM have been challenged, he said, by inconsistent reporting in trials of GDM diagnostic criteria, severity of hyperglycemia, and small sample sizes (and wide confidence intervals). Criteria for supplemental insulin are also often “unclear” in trials, Dr. Saade said, as is involvement of social determinants of health and the “care package” enveloping pharmacologic interventions.

Dr. Saade, Dr. Landon, and other researchers have also lamented over the years that there is limited long-term follow-up of exposed offspring.
 

The Challenge of Heterogeneity

In another presentation on GDM, Maisa Feghali, MD, MS, emphasized that GDM is a heterogeneous condition, with clinical hyperglycemia not capturing individual variation in underlying physiologic processes. A 2016 study (Diabetes Care. 2016;39[6]:1052-5) assessing insulin sensitivity and secretion in 800-plus women at 24-30 weeks’ gestation found that about 50% of those with GDM had predominant insulin resistance, 30% had predominant insulin secretion deficit, and 20% were mixed.

Those with predominant insulin resistance had higher BMI, higher fasting glucose, larger infants, and greater risk of GDM-associated adverse outcomes, “suggesting that the risk is not universal or equivalent,” said Dr. Feghali, assistant professor in the department of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh and the UPCM Magee-Women’s Hospital.

A 2019 multicenter European study (Diabetologia. 2019;62[11]:2118-28) found an even higher proportion of GDM involving predominant insulin resistance and, similarly, a greater risk of adverse pregnancy outcomes in these women than in insulin-sensitive women with GDM, “again suggesting that there’s probably some benefit to looking deeper at physiology to understand individual risk,” she said.

Research published decades ago showed that insulin sensitivity decreases by over 50% during pregnancy, and “what we’ve come to recognize is there [can be] insulin secretion deficiency that’s not able to surmount or overcome the insulin resistance that develops during advanced gestation,” she said. “We need to think not at the population level but at the individual level.”

Dr. Feghali is leading the MATCh-GDM (Metabolic Analysis for Treatment Choice in GDM) study, which has been randomizing women to receive either usual, unmatched treatment or treatment matched to GDM mechanism — metformin for predominant insulin resistance, glyburide, or insulin for predominant insulin secretion defects, and one of the three for combined mechanisms. Data are not available yet.

There is still more to be learned about the pharmacologic effects of oral hypoglycemics, she noted, pointing to a 2020 study (Clin Pharmacol Ther. 2020;107[6]:1362-72) that randomized women to glyburide, metformin, or glyburide/metformin combination therapy and measured insulin sensitivity, beta-cell responsivity, and disposition index. (The latter describes the overall metabolic state and is a product of insulin sensitivity and total beta-cell responsivity.)

“Somewhat surprisingly, they found metformin performed better than glyburide,” shifting the overall disposition index closer to normal, Dr. Feghali said. “But not surprisingly, they found the combination worked best.”

Total beta-cell responsivity occurred in 56% of the glyburide group and 74% of the combination group. Improvements in insulin sensitivity occurred in 84% of the metformin group and 74% of the combination group. Surprisingly, there was “a decrease in first-phase insulin secretion” with glyburide, noted Dr. Feghali — a finding that means “the glyburide story has turned out to be a little more complicated.” With metformin, there was a positive change in insulin secretion as well as insulin sensitivity.

The authors’ conclusion, she noted, “is that there’s potential in thinking about metformin first, as the primary treatment, and then adding glyburide after that.”
 

Future Use Of Incretin Mimetics, and Intensive Targets in Overweight/Obesity

Dr. Feghali wonders whether incretin hormone mimetics — such as glucagonlike peptide–1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) — could play a future role in GDM treatment, helping to increase insulin secretion.

She is currently recruiting for a pilot study on the pharmacokinetics and pharmacodynamics in GDM of exenatide, a FDA-approved GLP-1 agonist that has been shown not to cross the placenta and that should, research suggests, lower the risk of maternal hypoglycemia and limit the risk of excessive fetal growth, “overcoming some of the concerns we have with glyburide,” Dr. Feghali said.

A recent study of the gut-generated incretin response during an oral glucose tolerance test in pregnant women with and without GDM showed that post-load GLP-1 and GIP were higher in women with GDM, and that the GLP-1 secretion was associated with insulin secretion only in those with GDM (J Clin Endocrinol Metab. 2022;107(6):e2425-30). “In those with normal OGTT, insulin secretion was independent of GLP-1,” she said. “This study suggests there’s a potential role for incretin mimetics in GDM.”

Also regarding the individualization of GDM treatment, patients who are overweight or obese in the prepregnancy setting and have gestational diabetes represent a different phenotype, she noted, with higher fasting and postprandial blood glucose compared to normal-weight counterparts despite higher doses of medication.

“After controlling for gestational weight gain and glycemic control, we see there’s an independent effect of prepregnancy obesity specifically for an increased risk of macrosomia, preterm birth, and hypertensive disorders of pregnancy,” said Dr. Feghali, referring to a 2015 retrospective study of GDM and obesity (Obstet Gynecol. 2015;126:316-25). “It suggests that we might think about redrawing the line, not on diagnosis and screening but on treatment.”

The randomized, controlled Intensive Glycemic Targets in Overweight and Obese Women with Gestational Diabetes Mellitus (iGDM) trial, is now recruiting at multiple centers, including at Dr. Feghali’s University of Pittsburgh, and will investigate the effect of intensive glycemic targets (fasting < 90 mg/dL, 1-hour postprandial < 120 mg/dL) versus standard glycemic targets (fasting < 95 mg/dL, 1-hour postprandial < 140 mg/dL), she said.

In another presentation on GDM, Monica Longo, MD, PhD, of the Inova Health System in Fairfax, Va., said researchers are also looking at whether nutritional supplements such as myo-inositol can reduce the risk of adverse pregnancy outcomes in GDM, and whether probiotics can improve insulin sensitivity in some patients.

Data on newer insulin analogs in pregnancy are lacking, she noted. “Preliminary data has shown no malformations in infants, but there is some increase in hypoglycemia-related admissions to the NICU,” she said. “It’s worth it [to research more].”

FAIRFAX, VIRGINIA — Pharmacologic treatment of gestational diabetes mellitus (GDM) remains challenged by overall poor trial quality, clinical practice guidelines that offer differing advice, and a limited ability to predict individual risk and treatment response, but researchers at the biennial meeting of the Diabetes in Pregnancy Study Group of North America expressed hope for more clarity in the near future and the ability to someday individualize treatment to account for what is increasingly viewed as a heterogeneous condition.

Until studies in 2015 and 2018 cast doubt on glyburide, “we used to have 80% [of our GDM patients] on glyburide, and 20% on insulin,” Maisa Feghali, MD, of the University of Pittsburgh, said during a discussion period. “Now we have 95% on insulin and 5% on oral hypoglycemics. I rely on insulin because I don’t have a better option, and I rely on research efforts [underway to provide better options]” in the future.

The American College of Obstetricians and Gynecologists recommends insulin as the preferred first-line pharmacologic therapy for GDM when pharmacologic therapy is needed, with metformin as an option when patients decline or cannot safely use insulin. Glyburide, ACOG said in its 2018 practice bulletin on GDM (Obstet Gynecol. 2018;131[2]:e49-64), should not be recommended as a first-line pharmacologic therapy.

The Society of Maternal-Fetal Medicine, on the other hand, has accepted metformin as a “reasonable and safe” first-line alternative to insulin — while recognizing that half of women will still require insulin to achieve glycemic control — and does not rule out consideration of glyburide. In its 2018 statement on the pharmacologic treatment of GDM, the society said that the evidence of benefit of one oral agent over another remains limited.  

“When you have dueling guidelines, it means the data are not that clear,” George Saade, MD, professor and chair of obstetrics and gynecology at the Eastern Virginia School of Medicine, Norfolk, said in a presentation on GDM. An upcoming $12 million multicenter study to be led by the Ohio State University College of Medicine — coined the DECIDE trial — should provide clarity, he said.

The trial, funded by the Patient-Centered Outcomes Research Institute, which funds comparative clinical effectiveness research designed to be broadly applicable to practice, will enroll and randomize over 1500 pregnant individuals with GDM to either oral metformin or insulin and will follow mothers and children until 2 years after delivery.

The study’s primary and secondary hypotheses, respectively, are that metformin is not inferior to insulin in reducing a composite adverse neonatal outcome (large for gestational age, neonatal hypoglycemia and/or hyperbilirubemia) and that metformin does not result in increased child body mass index at 2 years, compared with insulin. It will also look at patient-reported factors associated with metformin use compared to insulin use — factors that “are important ... to enable clinical implementation of study findings,” said Dr. Saade, who played a role in designing the study over the past several years.

The study will take a pragmatic, real-world approach by ensuring racial and ethnic, socioeconomic, urban and rural, and geographic diversity at both large academic and community-based sites across the United States.

The trial, to be led by Mark Landon, MD, and Kartik Venkatesh, MD, PhD, of Ohio State University, will be the first large trial in the United States to both directly compare the ability of oral hypoglycemics and insulin to prevent GDM-associated pregnancy complications, and to follow children for 2 years, Dr. Saade said. “Prior research was either outside the United States, not randomized, not adequately powered, or had no long-term child follow-up,” he added after the meeting.
 

The State Of Knowledge About Oral Hypoglycemics

The trial was envisioned several years ago as a three-arm comparative trial including the sulfonylurea glyburide, but data published in recent years has increasingly “not favored” glyburide, and many providers “have stopped using it,” Dr. Saade said during and after the meeting. At this point, “it would not be useful to include it” in a pragmatic trial, he said.

Glyburide became the number one agent after a seminal trial published in 2000 (N Engl J Med. 2000;343:1134-8) showed equivalent glycemic control in about 400 women with GDM who were randomized to receive insulin or glyburide. While the trial was not powered to evaluate other outcomes, there were no significant differences in neonatal complications.

In 2015, a large retrospective population-based study (JAMA Pediatr. 2015;169[5]:452-8) of more than 9,000 women with GDM showed higher risks of neonatal intensive care admission, neonatal hypoglycemia, and large-for-gestational age with glyburide compared with insulin. “It prompted a pause in thinking,” Dr. Saade recalled at the DPSG meeting. After that, several meta-analyses/systematic reviews compared the two treatments, showing varying and sometimes conflicting degrees of difference in neonatal outcomes.

In 2018, a French noninferiority randomized controlled trial (JAMA 2018;319[17]:1773-80) did not show that glyburide is not inferior to insulin in the prevention of perinatal outcomes (macrosomia, neonatal hypoglycemia, and hyperbilirubinemia). “If you add this trial to the systematic reviews, it would probably would shift more in favor of insulin,” Dr. Saade said, noting that the trial’s supplementary data included a higher rate of maternal hypoglycemia with glyburide. “I feel personally now, with all the data, that glyburide is inferior to insulin.”

A 2021 network meta-analysis (BMC Endocr Disord. 2021;21:199) that looked at glycemic control and neonatal outcomes in GDM treated with glyburide, metformin, or insulin, also offers valuable insight, Dr. Saade said. The meta-analysis used a Bayesian framework and presents results as a ranking estimated probability of a treatment being the best or worst — or in between — for different outcomes (glycemic control and neonatal outcomes), which “is one of the best ways to look at data these days,” he said.

“It tells us how likely [it is for one agent] to be better than others. Will it work most of the time? More than 60% of the time?” Dr. Saade explained. For example, the analysis “tell us that for large for gestational age, glyburide has a 94% chance of being the worst, metformin has an 80% change of being the best, and insulin a 76% chance of being in between.”

Overall, the 2021 analysis suggests that “glyburide is the most likely to be worst in most outcomes and that there is equipoise between metformin and insulin,” he said.

Meta-analyses of pharmacologic treatment of GDM have been challenged, he said, by inconsistent reporting in trials of GDM diagnostic criteria, severity of hyperglycemia, and small sample sizes (and wide confidence intervals). Criteria for supplemental insulin are also often “unclear” in trials, Dr. Saade said, as is involvement of social determinants of health and the “care package” enveloping pharmacologic interventions.

Dr. Saade, Dr. Landon, and other researchers have also lamented over the years that there is limited long-term follow-up of exposed offspring.
 

The Challenge of Heterogeneity

In another presentation on GDM, Maisa Feghali, MD, MS, emphasized that GDM is a heterogeneous condition, with clinical hyperglycemia not capturing individual variation in underlying physiologic processes. A 2016 study (Diabetes Care. 2016;39[6]:1052-5) assessing insulin sensitivity and secretion in 800-plus women at 24-30 weeks’ gestation found that about 50% of those with GDM had predominant insulin resistance, 30% had predominant insulin secretion deficit, and 20% were mixed.

Those with predominant insulin resistance had higher BMI, higher fasting glucose, larger infants, and greater risk of GDM-associated adverse outcomes, “suggesting that the risk is not universal or equivalent,” said Dr. Feghali, assistant professor in the department of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh and the UPCM Magee-Women’s Hospital.

A 2019 multicenter European study (Diabetologia. 2019;62[11]:2118-28) found an even higher proportion of GDM involving predominant insulin resistance and, similarly, a greater risk of adverse pregnancy outcomes in these women than in insulin-sensitive women with GDM, “again suggesting that there’s probably some benefit to looking deeper at physiology to understand individual risk,” she said.

Research published decades ago showed that insulin sensitivity decreases by over 50% during pregnancy, and “what we’ve come to recognize is there [can be] insulin secretion deficiency that’s not able to surmount or overcome the insulin resistance that develops during advanced gestation,” she said. “We need to think not at the population level but at the individual level.”

Dr. Feghali is leading the MATCh-GDM (Metabolic Analysis for Treatment Choice in GDM) study, which has been randomizing women to receive either usual, unmatched treatment or treatment matched to GDM mechanism — metformin for predominant insulin resistance, glyburide, or insulin for predominant insulin secretion defects, and one of the three for combined mechanisms. Data are not available yet.

There is still more to be learned about the pharmacologic effects of oral hypoglycemics, she noted, pointing to a 2020 study (Clin Pharmacol Ther. 2020;107[6]:1362-72) that randomized women to glyburide, metformin, or glyburide/metformin combination therapy and measured insulin sensitivity, beta-cell responsivity, and disposition index. (The latter describes the overall metabolic state and is a product of insulin sensitivity and total beta-cell responsivity.)

“Somewhat surprisingly, they found metformin performed better than glyburide,” shifting the overall disposition index closer to normal, Dr. Feghali said. “But not surprisingly, they found the combination worked best.”

Total beta-cell responsivity occurred in 56% of the glyburide group and 74% of the combination group. Improvements in insulin sensitivity occurred in 84% of the metformin group and 74% of the combination group. Surprisingly, there was “a decrease in first-phase insulin secretion” with glyburide, noted Dr. Feghali — a finding that means “the glyburide story has turned out to be a little more complicated.” With metformin, there was a positive change in insulin secretion as well as insulin sensitivity.

The authors’ conclusion, she noted, “is that there’s potential in thinking about metformin first, as the primary treatment, and then adding glyburide after that.”
 

Future Use Of Incretin Mimetics, and Intensive Targets in Overweight/Obesity

Dr. Feghali wonders whether incretin hormone mimetics — such as glucagonlike peptide–1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) — could play a future role in GDM treatment, helping to increase insulin secretion.

She is currently recruiting for a pilot study on the pharmacokinetics and pharmacodynamics in GDM of exenatide, a FDA-approved GLP-1 agonist that has been shown not to cross the placenta and that should, research suggests, lower the risk of maternal hypoglycemia and limit the risk of excessive fetal growth, “overcoming some of the concerns we have with glyburide,” Dr. Feghali said.

A recent study of the gut-generated incretin response during an oral glucose tolerance test in pregnant women with and without GDM showed that post-load GLP-1 and GIP were higher in women with GDM, and that the GLP-1 secretion was associated with insulin secretion only in those with GDM (J Clin Endocrinol Metab. 2022;107(6):e2425-30). “In those with normal OGTT, insulin secretion was independent of GLP-1,” she said. “This study suggests there’s a potential role for incretin mimetics in GDM.”

Also regarding the individualization of GDM treatment, patients who are overweight or obese in the prepregnancy setting and have gestational diabetes represent a different phenotype, she noted, with higher fasting and postprandial blood glucose compared to normal-weight counterparts despite higher doses of medication.

“After controlling for gestational weight gain and glycemic control, we see there’s an independent effect of prepregnancy obesity specifically for an increased risk of macrosomia, preterm birth, and hypertensive disorders of pregnancy,” said Dr. Feghali, referring to a 2015 retrospective study of GDM and obesity (Obstet Gynecol. 2015;126:316-25). “It suggests that we might think about redrawing the line, not on diagnosis and screening but on treatment.”

The randomized, controlled Intensive Glycemic Targets in Overweight and Obese Women with Gestational Diabetes Mellitus (iGDM) trial, is now recruiting at multiple centers, including at Dr. Feghali’s University of Pittsburgh, and will investigate the effect of intensive glycemic targets (fasting < 90 mg/dL, 1-hour postprandial < 120 mg/dL) versus standard glycemic targets (fasting < 95 mg/dL, 1-hour postprandial < 140 mg/dL), she said.

In another presentation on GDM, Monica Longo, MD, PhD, of the Inova Health System in Fairfax, Va., said researchers are also looking at whether nutritional supplements such as myo-inositol can reduce the risk of adverse pregnancy outcomes in GDM, and whether probiotics can improve insulin sensitivity in some patients.

Data on newer insulin analogs in pregnancy are lacking, she noted. “Preliminary data has shown no malformations in infants, but there is some increase in hypoglycemia-related admissions to the NICU,” she said. “It’s worth it [to research more].”

FAIRFAX, VIRGINIA — Pharmacologic treatment of gestational diabetes mellitus (GDM) remains challenged by overall poor trial quality, clinical practice guidelines that offer differing advice, and a limited ability to predict individual risk and treatment response, but researchers at the biennial meeting of the Diabetes in Pregnancy Study Group of North America expressed hope for more clarity in the near future and the ability to someday individualize treatment to account for what is increasingly viewed as a heterogeneous condition.

Until studies in 2015 and 2018 cast doubt on glyburide, “we used to have 80% [of our GDM patients] on glyburide, and 20% on insulin,” Maisa Feghali, MD, of the University of Pittsburgh, said during a discussion period. “Now we have 95% on insulin and 5% on oral hypoglycemics. I rely on insulin because I don’t have a better option, and I rely on research efforts [underway to provide better options]” in the future.

The American College of Obstetricians and Gynecologists recommends insulin as the preferred first-line pharmacologic therapy for GDM when pharmacologic therapy is needed, with metformin as an option when patients decline or cannot safely use insulin. Glyburide, ACOG said in its 2018 practice bulletin on GDM (Obstet Gynecol. 2018;131[2]:e49-64), should not be recommended as a first-line pharmacologic therapy.

The Society of Maternal-Fetal Medicine, on the other hand, has accepted metformin as a “reasonable and safe” first-line alternative to insulin — while recognizing that half of women will still require insulin to achieve glycemic control — and does not rule out consideration of glyburide. In its 2018 statement on the pharmacologic treatment of GDM, the society said that the evidence of benefit of one oral agent over another remains limited.  

“When you have dueling guidelines, it means the data are not that clear,” George Saade, MD, professor and chair of obstetrics and gynecology at the Eastern Virginia School of Medicine, Norfolk, said in a presentation on GDM. An upcoming $12 million multicenter study to be led by the Ohio State University College of Medicine — coined the DECIDE trial — should provide clarity, he said.

The trial, funded by the Patient-Centered Outcomes Research Institute, which funds comparative clinical effectiveness research designed to be broadly applicable to practice, will enroll and randomize over 1500 pregnant individuals with GDM to either oral metformin or insulin and will follow mothers and children until 2 years after delivery.

The study’s primary and secondary hypotheses, respectively, are that metformin is not inferior to insulin in reducing a composite adverse neonatal outcome (large for gestational age, neonatal hypoglycemia and/or hyperbilirubemia) and that metformin does not result in increased child body mass index at 2 years, compared with insulin. It will also look at patient-reported factors associated with metformin use compared to insulin use — factors that “are important ... to enable clinical implementation of study findings,” said Dr. Saade, who played a role in designing the study over the past several years.

The study will take a pragmatic, real-world approach by ensuring racial and ethnic, socioeconomic, urban and rural, and geographic diversity at both large academic and community-based sites across the United States.

The trial, to be led by Mark Landon, MD, and Kartik Venkatesh, MD, PhD, of Ohio State University, will be the first large trial in the United States to both directly compare the ability of oral hypoglycemics and insulin to prevent GDM-associated pregnancy complications, and to follow children for 2 years, Dr. Saade said. “Prior research was either outside the United States, not randomized, not adequately powered, or had no long-term child follow-up,” he added after the meeting.
 

The State Of Knowledge About Oral Hypoglycemics

The trial was envisioned several years ago as a three-arm comparative trial including the sulfonylurea glyburide, but data published in recent years has increasingly “not favored” glyburide, and many providers “have stopped using it,” Dr. Saade said during and after the meeting. At this point, “it would not be useful to include it” in a pragmatic trial, he said.

Glyburide became the number one agent after a seminal trial published in 2000 (N Engl J Med. 2000;343:1134-8) showed equivalent glycemic control in about 400 women with GDM who were randomized to receive insulin or glyburide. While the trial was not powered to evaluate other outcomes, there were no significant differences in neonatal complications.

In 2015, a large retrospective population-based study (JAMA Pediatr. 2015;169[5]:452-8) of more than 9,000 women with GDM showed higher risks of neonatal intensive care admission, neonatal hypoglycemia, and large-for-gestational age with glyburide compared with insulin. “It prompted a pause in thinking,” Dr. Saade recalled at the DPSG meeting. After that, several meta-analyses/systematic reviews compared the two treatments, showing varying and sometimes conflicting degrees of difference in neonatal outcomes.

In 2018, a French noninferiority randomized controlled trial (JAMA 2018;319[17]:1773-80) did not show that glyburide is not inferior to insulin in the prevention of perinatal outcomes (macrosomia, neonatal hypoglycemia, and hyperbilirubinemia). “If you add this trial to the systematic reviews, it would probably would shift more in favor of insulin,” Dr. Saade said, noting that the trial’s supplementary data included a higher rate of maternal hypoglycemia with glyburide. “I feel personally now, with all the data, that glyburide is inferior to insulin.”

A 2021 network meta-analysis (BMC Endocr Disord. 2021;21:199) that looked at glycemic control and neonatal outcomes in GDM treated with glyburide, metformin, or insulin, also offers valuable insight, Dr. Saade said. The meta-analysis used a Bayesian framework and presents results as a ranking estimated probability of a treatment being the best or worst — or in between — for different outcomes (glycemic control and neonatal outcomes), which “is one of the best ways to look at data these days,” he said.

“It tells us how likely [it is for one agent] to be better than others. Will it work most of the time? More than 60% of the time?” Dr. Saade explained. For example, the analysis “tell us that for large for gestational age, glyburide has a 94% chance of being the worst, metformin has an 80% change of being the best, and insulin a 76% chance of being in between.”

Overall, the 2021 analysis suggests that “glyburide is the most likely to be worst in most outcomes and that there is equipoise between metformin and insulin,” he said.

Meta-analyses of pharmacologic treatment of GDM have been challenged, he said, by inconsistent reporting in trials of GDM diagnostic criteria, severity of hyperglycemia, and small sample sizes (and wide confidence intervals). Criteria for supplemental insulin are also often “unclear” in trials, Dr. Saade said, as is involvement of social determinants of health and the “care package” enveloping pharmacologic interventions.

Dr. Saade, Dr. Landon, and other researchers have also lamented over the years that there is limited long-term follow-up of exposed offspring.
 

The Challenge of Heterogeneity

In another presentation on GDM, Maisa Feghali, MD, MS, emphasized that GDM is a heterogeneous condition, with clinical hyperglycemia not capturing individual variation in underlying physiologic processes. A 2016 study (Diabetes Care. 2016;39[6]:1052-5) assessing insulin sensitivity and secretion in 800-plus women at 24-30 weeks’ gestation found that about 50% of those with GDM had predominant insulin resistance, 30% had predominant insulin secretion deficit, and 20% were mixed.

Those with predominant insulin resistance had higher BMI, higher fasting glucose, larger infants, and greater risk of GDM-associated adverse outcomes, “suggesting that the risk is not universal or equivalent,” said Dr. Feghali, assistant professor in the department of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh and the UPCM Magee-Women’s Hospital.

A 2019 multicenter European study (Diabetologia. 2019;62[11]:2118-28) found an even higher proportion of GDM involving predominant insulin resistance and, similarly, a greater risk of adverse pregnancy outcomes in these women than in insulin-sensitive women with GDM, “again suggesting that there’s probably some benefit to looking deeper at physiology to understand individual risk,” she said.

Research published decades ago showed that insulin sensitivity decreases by over 50% during pregnancy, and “what we’ve come to recognize is there [can be] insulin secretion deficiency that’s not able to surmount or overcome the insulin resistance that develops during advanced gestation,” she said. “We need to think not at the population level but at the individual level.”

Dr. Feghali is leading the MATCh-GDM (Metabolic Analysis for Treatment Choice in GDM) study, which has been randomizing women to receive either usual, unmatched treatment or treatment matched to GDM mechanism — metformin for predominant insulin resistance, glyburide, or insulin for predominant insulin secretion defects, and one of the three for combined mechanisms. Data are not available yet.

There is still more to be learned about the pharmacologic effects of oral hypoglycemics, she noted, pointing to a 2020 study (Clin Pharmacol Ther. 2020;107[6]:1362-72) that randomized women to glyburide, metformin, or glyburide/metformin combination therapy and measured insulin sensitivity, beta-cell responsivity, and disposition index. (The latter describes the overall metabolic state and is a product of insulin sensitivity and total beta-cell responsivity.)

“Somewhat surprisingly, they found metformin performed better than glyburide,” shifting the overall disposition index closer to normal, Dr. Feghali said. “But not surprisingly, they found the combination worked best.”

Total beta-cell responsivity occurred in 56% of the glyburide group and 74% of the combination group. Improvements in insulin sensitivity occurred in 84% of the metformin group and 74% of the combination group. Surprisingly, there was “a decrease in first-phase insulin secretion” with glyburide, noted Dr. Feghali — a finding that means “the glyburide story has turned out to be a little more complicated.” With metformin, there was a positive change in insulin secretion as well as insulin sensitivity.

The authors’ conclusion, she noted, “is that there’s potential in thinking about metformin first, as the primary treatment, and then adding glyburide after that.”
 

Future Use Of Incretin Mimetics, and Intensive Targets in Overweight/Obesity

Dr. Feghali wonders whether incretin hormone mimetics — such as glucagonlike peptide–1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) — could play a future role in GDM treatment, helping to increase insulin secretion.

She is currently recruiting for a pilot study on the pharmacokinetics and pharmacodynamics in GDM of exenatide, a FDA-approved GLP-1 agonist that has been shown not to cross the placenta and that should, research suggests, lower the risk of maternal hypoglycemia and limit the risk of excessive fetal growth, “overcoming some of the concerns we have with glyburide,” Dr. Feghali said.

A recent study of the gut-generated incretin response during an oral glucose tolerance test in pregnant women with and without GDM showed that post-load GLP-1 and GIP were higher in women with GDM, and that the GLP-1 secretion was associated with insulin secretion only in those with GDM (J Clin Endocrinol Metab. 2022;107(6):e2425-30). “In those with normal OGTT, insulin secretion was independent of GLP-1,” she said. “This study suggests there’s a potential role for incretin mimetics in GDM.”

Also regarding the individualization of GDM treatment, patients who are overweight or obese in the prepregnancy setting and have gestational diabetes represent a different phenotype, she noted, with higher fasting and postprandial blood glucose compared to normal-weight counterparts despite higher doses of medication.

“After controlling for gestational weight gain and glycemic control, we see there’s an independent effect of prepregnancy obesity specifically for an increased risk of macrosomia, preterm birth, and hypertensive disorders of pregnancy,” said Dr. Feghali, referring to a 2015 retrospective study of GDM and obesity (Obstet Gynecol. 2015;126:316-25). “It suggests that we might think about redrawing the line, not on diagnosis and screening but on treatment.”

The randomized, controlled Intensive Glycemic Targets in Overweight and Obese Women with Gestational Diabetes Mellitus (iGDM) trial, is now recruiting at multiple centers, including at Dr. Feghali’s University of Pittsburgh, and will investigate the effect of intensive glycemic targets (fasting < 90 mg/dL, 1-hour postprandial < 120 mg/dL) versus standard glycemic targets (fasting < 95 mg/dL, 1-hour postprandial < 140 mg/dL), she said.

In another presentation on GDM, Monica Longo, MD, PhD, of the Inova Health System in Fairfax, Va., said researchers are also looking at whether nutritional supplements such as myo-inositol can reduce the risk of adverse pregnancy outcomes in GDM, and whether probiotics can improve insulin sensitivity in some patients.

Data on newer insulin analogs in pregnancy are lacking, she noted. “Preliminary data has shown no malformations in infants, but there is some increase in hypoglycemia-related admissions to the NICU,” she said. “It’s worth it [to research more].”