Lia Vellardita, MA

Possibly. Elevated body mass index (BMI) is associated with an increased risk for stillbirth (strength of recommendation (SOR), B; Cohort studies and meta-analysis of cohort studies). Three studies found an association between elevated BMI and stillbirth and one did not. However, no studies demonstrate that antenatal testing in pregnant people with higher BMIs decreases stillbirth rates, or that no harm is caused by unnecessary testing or resultant interventions.

Still, in 2021, the American College of Obstetricians and Gynecologists (ACOG) suggested weekly antenatal testing may be considered from 34 weeks' 0 days' gestation for pregnant people with a BMI ≥ 40.0 kg/m² and from 37 weeks' 0 days' gestation for pregnant people with a BMI between 35.0 and 39.9 kg/m² (SOR, C; consensus guideline). Thus, doing the antenatal testing recommended in the ACOG guideline in an attempt to prevent stillbirth is reasonable, given evidence that elevated BMI is associated with stillbirth.

Evidence summary

Association between higher maternal BMI and increased risk for stillbirth

The purpose of antenatal testing is to decrease the risk for stillbirth between visits. Because of the resources involved and the risk for false-positives when testing low-risk patients, antenatal testing is reserved for pregnant people with higher risk for stillbirth.

In a retrospective cohort study of more than 2.8 million singleton births including 9,030 stillbirths, pregnant people with an elevated BMI had an increased risk for stillbirth compared with those with a normal BMI. The adjusted hazard ratio was 1.71 (95% confidence interval (CI), 1.62-1.83) for those with a BMI of 30.0 to 34.9 kg/m²; 2.04 (95% CI, 1.8-2.21) for those with a BMI of 35.0 to 39.9 kg/m²; and 2.50 (95% CI, 2.28-2.74) for those with a BMI ≥ 40 kg/m².¹

A meta-analysis of 38 studies, which included data on 16,274 stillbirths, found that a 5-unit increase in BMI was associated with an increased risk for stillbirth (relative risk, 1.24; 95% CI, 1.18-1.30).²

Another meta-analysis included 6 cohort studies involving more than 1 million pregnancies and 3 case-control studies involving 2,530 stillbirths and 2,837 controls from 1980-2005. There was an association between increasing BMI and stillbirth: the odds ratio (OR) was 1.47 (95% CI, 1.08-1.94) for those with a BMI of 25.0 to 29.9 kg/m² and 2.07 (95% CI, 1.59-2.74) for those with a BMI ≥ 30.0, compared with those with a normal BMI.³

However, a retrospective cohort study of 182,362 singleton births including 442 stillbirths found no association between stillbirth and increasing BMI. The OR was 1.10 (95% CI, 0.90-1.36) for those with a BMI of 25.0 to 29.9 and 1.09 (95% CI, 0.87-1.37) for those with a BMI ≥ 30.0 kg/m2, compared with those with a normal BMI.⁴ However, this cohort study may have been underpowered to detect an association between stillbirth and BMI.

Recommendations from others

In 2021, ACOG suggested that weekly antenatal testing may be considered from 34 weeks' and 0 days' gestation for pregnant people with a BMI ≥ 40.0 kg/m² and from 37 weeks' and 0 days' gestation for pregnant people with a BMI between 35.0 and 39.9 kg/m².⁵ The 2021 ACOG Practice Bulletin on obesity in pregnancy rates this recommendation as Level C—based primarily on consensus and expert opinion.⁶

A 2018 Royal College of Obstetricians and Gynecologists Green-top Guideline recognizes “definitive recommendations for fetal surveillance are hampered by the lack of randomized controlled trials demonstrating that antepartum fetal surveillance decreases perinatal morbidity or mortality in late-term and post-term gestations…. There are no definitive studies determining the optimal type or frequency of such testing and no evidence specific for women with obesity.”⁷

A 2019 Society of Obstetricians and Gynecologists of Canada practice guideline states “stillbirth is more common with maternal obesity” and recommends “increased fetal surveillance … in the third trimester if reduced fetal movements are reported.” The guideline notes “the role for non-stress tests … in surveillance of well-being in this population is uncertain.” Also, for pregnant people with a BMI > 30 kg/m², “assessment of fetal well-being is … recommended weekly from 37 weeks until delivery.” Finally, increased fetal surveillance is recommended in the setting of increased BMI and an abnormal pulsatility index of the umbilical artery and/or maternal uterine artery.⁸

Editor’s takeaway

Evidence demonstrates that increased maternal BMI is associated with increased stillbirths. However, evidence has not shown that third-trimester antenatal testing decreases this morbidity and mortality. Expert opinion varies, with ACOG recommending weekly antenatal testing from 34 and 37 weeks’ gestation, respectively, for pregnant people with BMIs of ≥ 40 kg/m² and of 35 to 39.9 kg/m². ●

Possibly. Elevated body mass index (BMI) is associated with an increased risk for stillbirth (strength of recommendation (SOR), B; Cohort studies and meta-analysis of cohort studies). Three studies found an association between elevated BMI and stillbirth and one did not. However, no studies demonstrate that antenatal testing in pregnant people with higher BMIs decreases stillbirth rates, or that no harm is caused by unnecessary testing or resultant interventions.

Still, in 2021, the American College of Obstetricians and Gynecologists (ACOG) suggested weekly antenatal testing may be considered from 34 weeks' 0 days' gestation for pregnant people with a BMI ≥ 40.0 kg/m² and from 37 weeks' 0 days' gestation for pregnant people with a BMI between 35.0 and 39.9 kg/m² (SOR, C; consensus guideline). Thus, doing the antenatal testing recommended in the ACOG guideline in an attempt to prevent stillbirth is reasonable, given evidence that elevated BMI is associated with stillbirth.

Evidence summary

Association between higher maternal BMI and increased risk for stillbirth

The purpose of antenatal testing is to decrease the risk for stillbirth between visits. Because of the resources involved and the risk for false-positives when testing low-risk patients, antenatal testing is reserved for pregnant people with higher risk for stillbirth.

In a retrospective cohort study of more than 2.8 million singleton births including 9,030 stillbirths, pregnant people with an elevated BMI had an increased risk for stillbirth compared with those with a normal BMI. The adjusted hazard ratio was 1.71 (95% confidence interval (CI), 1.62-1.83) for those with a BMI of 30.0 to 34.9 kg/m²; 2.04 (95% CI, 1.8-2.21) for those with a BMI of 35.0 to 39.9 kg/m²; and 2.50 (95% CI, 2.28-2.74) for those with a BMI ≥ 40 kg/m².¹

A meta-analysis of 38 studies, which included data on 16,274 stillbirths, found that a 5-unit increase in BMI was associated with an increased risk for stillbirth (relative risk, 1.24; 95% CI, 1.18-1.30).²

Another meta-analysis included 6 cohort studies involving more than 1 million pregnancies and 3 case-control studies involving 2,530 stillbirths and 2,837 controls from 1980-2005. There was an association between increasing BMI and stillbirth: the odds ratio (OR) was 1.47 (95% CI, 1.08-1.94) for those with a BMI of 25.0 to 29.9 kg/m² and 2.07 (95% CI, 1.59-2.74) for those with a BMI ≥ 30.0, compared with those with a normal BMI.³

However, a retrospective cohort study of 182,362 singleton births including 442 stillbirths found no association between stillbirth and increasing BMI. The OR was 1.10 (95% CI, 0.90-1.36) for those with a BMI of 25.0 to 29.9 and 1.09 (95% CI, 0.87-1.37) for those with a BMI ≥ 30.0 kg/m2, compared with those with a normal BMI.⁴ However, this cohort study may have been underpowered to detect an association between stillbirth and BMI.

Recommendations from others

In 2021, ACOG suggested that weekly antenatal testing may be considered from 34 weeks' and 0 days' gestation for pregnant people with a BMI ≥ 40.0 kg/m² and from 37 weeks' and 0 days' gestation for pregnant people with a BMI between 35.0 and 39.9 kg/m².⁵ The 2021 ACOG Practice Bulletin on obesity in pregnancy rates this recommendation as Level C—based primarily on consensus and expert opinion.⁶

A 2018 Royal College of Obstetricians and Gynecologists Green-top Guideline recognizes “definitive recommendations for fetal surveillance are hampered by the lack of randomized controlled trials demonstrating that antepartum fetal surveillance decreases perinatal morbidity or mortality in late-term and post-term gestations…. There are no definitive studies determining the optimal type or frequency of such testing and no evidence specific for women with obesity.”⁷

A 2019 Society of Obstetricians and Gynecologists of Canada practice guideline states “stillbirth is more common with maternal obesity” and recommends “increased fetal surveillance … in the third trimester if reduced fetal movements are reported.” The guideline notes “the role for non-stress tests … in surveillance of well-being in this population is uncertain.” Also, for pregnant people with a BMI > 30 kg/m², “assessment of fetal well-being is … recommended weekly from 37 weeks until delivery.” Finally, increased fetal surveillance is recommended in the setting of increased BMI and an abnormal pulsatility index of the umbilical artery and/or maternal uterine artery.⁸

Editor’s takeaway

Evidence demonstrates that increased maternal BMI is associated with increased stillbirths. However, evidence has not shown that third-trimester antenatal testing decreases this morbidity and mortality. Expert opinion varies, with ACOG recommending weekly antenatal testing from 34 and 37 weeks’ gestation, respectively, for pregnant people with BMIs of ≥ 40 kg/m² and of 35 to 39.9 kg/m². ●

Possibly. Elevated body mass index (BMI) is associated with an increased risk for stillbirth (strength of recommendation (SOR), B; Cohort studies and meta-analysis of cohort studies). Three studies found an association between elevated BMI and stillbirth and one did not. However, no studies demonstrate that antenatal testing in pregnant people with higher BMIs decreases stillbirth rates, or that no harm is caused by unnecessary testing or resultant interventions.

Still, in 2021, the American College of Obstetricians and Gynecologists (ACOG) suggested weekly antenatal testing may be considered from 34 weeks' 0 days' gestation for pregnant people with a BMI ≥ 40.0 kg/m² and from 37 weeks' 0 days' gestation for pregnant people with a BMI between 35.0 and 39.9 kg/m² (SOR, C; consensus guideline). Thus, doing the antenatal testing recommended in the ACOG guideline in an attempt to prevent stillbirth is reasonable, given evidence that elevated BMI is associated with stillbirth.

Evidence summary

Association between higher maternal BMI and increased risk for stillbirth

The purpose of antenatal testing is to decrease the risk for stillbirth between visits. Because of the resources involved and the risk for false-positives when testing low-risk patients, antenatal testing is reserved for pregnant people with higher risk for stillbirth.

In a retrospective cohort study of more than 2.8 million singleton births including 9,030 stillbirths, pregnant people with an elevated BMI had an increased risk for stillbirth compared with those with a normal BMI. The adjusted hazard ratio was 1.71 (95% confidence interval (CI), 1.62-1.83) for those with a BMI of 30.0 to 34.9 kg/m²; 2.04 (95% CI, 1.8-2.21) for those with a BMI of 35.0 to 39.9 kg/m²; and 2.50 (95% CI, 2.28-2.74) for those with a BMI ≥ 40 kg/m².¹

A meta-analysis of 38 studies, which included data on 16,274 stillbirths, found that a 5-unit increase in BMI was associated with an increased risk for stillbirth (relative risk, 1.24; 95% CI, 1.18-1.30).²

Another meta-analysis included 6 cohort studies involving more than 1 million pregnancies and 3 case-control studies involving 2,530 stillbirths and 2,837 controls from 1980-2005. There was an association between increasing BMI and stillbirth: the odds ratio (OR) was 1.47 (95% CI, 1.08-1.94) for those with a BMI of 25.0 to 29.9 kg/m² and 2.07 (95% CI, 1.59-2.74) for those with a BMI ≥ 30.0, compared with those with a normal BMI.³

However, a retrospective cohort study of 182,362 singleton births including 442 stillbirths found no association between stillbirth and increasing BMI. The OR was 1.10 (95% CI, 0.90-1.36) for those with a BMI of 25.0 to 29.9 and 1.09 (95% CI, 0.87-1.37) for those with a BMI ≥ 30.0 kg/m2, compared with those with a normal BMI.⁴ However, this cohort study may have been underpowered to detect an association between stillbirth and BMI.

Recommendations from others

In 2021, ACOG suggested that weekly antenatal testing may be considered from 34 weeks' and 0 days' gestation for pregnant people with a BMI ≥ 40.0 kg/m² and from 37 weeks' and 0 days' gestation for pregnant people with a BMI between 35.0 and 39.9 kg/m².⁵ The 2021 ACOG Practice Bulletin on obesity in pregnancy rates this recommendation as Level C—based primarily on consensus and expert opinion.⁶

A 2018 Royal College of Obstetricians and Gynecologists Green-top Guideline recognizes “definitive recommendations for fetal surveillance are hampered by the lack of randomized controlled trials demonstrating that antepartum fetal surveillance decreases perinatal morbidity or mortality in late-term and post-term gestations…. There are no definitive studies determining the optimal type or frequency of such testing and no evidence specific for women with obesity.”⁷

A 2019 Society of Obstetricians and Gynecologists of Canada practice guideline states “stillbirth is more common with maternal obesity” and recommends “increased fetal surveillance … in the third trimester if reduced fetal movements are reported.” The guideline notes “the role for non-stress tests … in surveillance of well-being in this population is uncertain.” Also, for pregnant people with a BMI > 30 kg/m², “assessment of fetal well-being is … recommended weekly from 37 weeks until delivery.” Finally, increased fetal surveillance is recommended in the setting of increased BMI and an abnormal pulsatility index of the umbilical artery and/or maternal uterine artery.⁸

Editor’s takeaway

Evidence demonstrates that increased maternal BMI is associated with increased stillbirths. However, evidence has not shown that third-trimester antenatal testing decreases this morbidity and mortality. Expert opinion varies, with ACOG recommending weekly antenatal testing from 34 and 37 weeks’ gestation, respectively, for pregnant people with BMIs of ≥ 40 kg/m² and of 35 to 39.9 kg/m². ●

Evidence summary

Association between higher maternal BMI and increased risk for stillbirth

The purpose of antenatal testing is to decrease the risk for stillbirth between visits. Because of the resources involved and the risk for false-positives when testing low-risk patients, antenatal testing is reserved for pregnant people with higher risk for stillbirth.

In a retrospective cohort study of more than 2.8 million singleton births including 9030 stillbirths, pregnant people with an ­elevated BMI had an increased risk for stillbirth compared to those with a normal BMI. The adjusted hazard ratio was 1.71 (95% CI, 1.62-1.83) for those with a BMI of 30.0 to 34.9; 2.04 (95% CI, 1.8-2.21) for those with a BMI of 35.0 to 39.9; and 2.50 (95% CI, 2.28-2.74) for those with a BMI ≥ 40.¹

A meta-analysis of 38 studies, which included data on 16,274 stillbirths, found that a 5-unit increase in BMI was associated with an increased risk for stillbirth (relative risk, 1.24; 95% CI, 1.18-1.30).²

Another meta-analysis included 6 cohort studies involving more than 1 million pregnancies and 3 case-control studies involving 2530 stillbirths and 2837 controls from 1980-2005. There was an association between increasing BMI and stillbirth: the odds ratio (OR) was 1.47 (95% CI, 1.08-1.94) for those with a BMI of 25.0 to 29.9 and 2.07 (95% CI, 1.59-2.74) for those with a BMI ≥ 30.0, compared to those with a normal BMI.³

However, a retrospective cohort study of 182,362 singleton births including 442 stillbirths found no association between stillbirth and increasing BMI. The OR was 1.10 (95% CI, 0.90-1.36) for those with a BMI of 25.0 to 29.9 and 1.09 (95% CI, 0.87-1.37) for those with a BMI ≥ 30.0, compared to those with a normal BMI.⁴ However, this cohort study may have been underpowered to detect an association between stillbirth and BMI.

Recommendations from others

In 2021, ACOG suggested that weekly antenatal testing may be considered from 34w0d for pregnant people with a BMI ≥ 40.0 and from 37w0d for pregnant people with a BMI between 35.0 and 39.9.⁵ The 2021 ACOG Practice Bulletin on Obesity in Pregnancy rates this recommendation as Level C—based primarily on consensus and expert opinion.⁶

A 2018 Royal College of Obstetricians and Gynecologists Green-top Guideline recognizes “definitive recommendations for fetal surveillance are hampered by the lack of randomized controlled trials demonstrating that antepartum fetal surveillance decreases perinatal morbidity or mortality in late-term and post-term gestations…. There are no definitive studies determining the optimal type or frequency of such testing and no evidence specific for women with obesity.”⁷

A 2019 Society of Obstetricians and Gynecologists of Canada practice guideline states “stillbirth is more common with maternal obesity” and recommends “increased fetal surveillance … in the third trimester if reduced fetal movements are reported.” The guideline notes “the role for non-stress tests … in surveillance of well-being in this population is uncertain.” Also, for pregnant people with a BMI > 30, “assessment of fetal well-being is … recommended weekly from 37 weeks until delivery.” Finally, increased fetal surveillance is recommended in the setting of increased BMI and an abnormal pulsatility index of the umbilical artery and/or maternal uterine artery.⁸

Editor’s takeaway

Evidence demonstrates that increased maternal BMI is associated with increased stillbirths. However, evidence has not shown that third-trimester antenatal testing decreases this morbidity and mortality. Expert opinion varies, with ACOG recommending weekly antenatal testing from 34 and 37 weeks for pregnant people with a BMI ≥ 40 and of 35 to 39.9, respectively.

Evidence summary

Association between higher maternal BMI and increased risk for stillbirth

The purpose of antenatal testing is to decrease the risk for stillbirth between visits. Because of the resources involved and the risk for false-positives when testing low-risk patients, antenatal testing is reserved for pregnant people with higher risk for stillbirth.

In a retrospective cohort study of more than 2.8 million singleton births including 9030 stillbirths, pregnant people with an ­elevated BMI had an increased risk for stillbirth compared to those with a normal BMI. The adjusted hazard ratio was 1.71 (95% CI, 1.62-1.83) for those with a BMI of 30.0 to 34.9; 2.04 (95% CI, 1.8-2.21) for those with a BMI of 35.0 to 39.9; and 2.50 (95% CI, 2.28-2.74) for those with a BMI ≥ 40.¹

A meta-analysis of 38 studies, which included data on 16,274 stillbirths, found that a 5-unit increase in BMI was associated with an increased risk for stillbirth (relative risk, 1.24; 95% CI, 1.18-1.30).²

Another meta-analysis included 6 cohort studies involving more than 1 million pregnancies and 3 case-control studies involving 2530 stillbirths and 2837 controls from 1980-2005. There was an association between increasing BMI and stillbirth: the odds ratio (OR) was 1.47 (95% CI, 1.08-1.94) for those with a BMI of 25.0 to 29.9 and 2.07 (95% CI, 1.59-2.74) for those with a BMI ≥ 30.0, compared to those with a normal BMI.³

However, a retrospective cohort study of 182,362 singleton births including 442 stillbirths found no association between stillbirth and increasing BMI. The OR was 1.10 (95% CI, 0.90-1.36) for those with a BMI of 25.0 to 29.9 and 1.09 (95% CI, 0.87-1.37) for those with a BMI ≥ 30.0, compared to those with a normal BMI.⁴ However, this cohort study may have been underpowered to detect an association between stillbirth and BMI.

Recommendations from others

In 2021, ACOG suggested that weekly antenatal testing may be considered from 34w0d for pregnant people with a BMI ≥ 40.0 and from 37w0d for pregnant people with a BMI between 35.0 and 39.9.⁵ The 2021 ACOG Practice Bulletin on Obesity in Pregnancy rates this recommendation as Level C—based primarily on consensus and expert opinion.⁶

A 2018 Royal College of Obstetricians and Gynecologists Green-top Guideline recognizes “definitive recommendations for fetal surveillance are hampered by the lack of randomized controlled trials demonstrating that antepartum fetal surveillance decreases perinatal morbidity or mortality in late-term and post-term gestations…. There are no definitive studies determining the optimal type or frequency of such testing and no evidence specific for women with obesity.”⁷

A 2019 Society of Obstetricians and Gynecologists of Canada practice guideline states “stillbirth is more common with maternal obesity” and recommends “increased fetal surveillance … in the third trimester if reduced fetal movements are reported.” The guideline notes “the role for non-stress tests … in surveillance of well-being in this population is uncertain.” Also, for pregnant people with a BMI > 30, “assessment of fetal well-being is … recommended weekly from 37 weeks until delivery.” Finally, increased fetal surveillance is recommended in the setting of increased BMI and an abnormal pulsatility index of the umbilical artery and/or maternal uterine artery.⁸

Editor’s takeaway

Evidence demonstrates that increased maternal BMI is associated with increased stillbirths. However, evidence has not shown that third-trimester antenatal testing decreases this morbidity and mortality. Expert opinion varies, with ACOG recommending weekly antenatal testing from 34 and 37 weeks for pregnant people with a BMI ≥ 40 and of 35 to 39.9, respectively.

Evidence summary

Association between higher maternal BMI and increased risk for stillbirth

The purpose of antenatal testing is to decrease the risk for stillbirth between visits. Because of the resources involved and the risk for false-positives when testing low-risk patients, antenatal testing is reserved for pregnant people with higher risk for stillbirth.

In a retrospective cohort study of more than 2.8 million singleton births including 9030 stillbirths, pregnant people with an ­elevated BMI had an increased risk for stillbirth compared to those with a normal BMI. The adjusted hazard ratio was 1.71 (95% CI, 1.62-1.83) for those with a BMI of 30.0 to 34.9; 2.04 (95% CI, 1.8-2.21) for those with a BMI of 35.0 to 39.9; and 2.50 (95% CI, 2.28-2.74) for those with a BMI ≥ 40.¹

A meta-analysis of 38 studies, which included data on 16,274 stillbirths, found that a 5-unit increase in BMI was associated with an increased risk for stillbirth (relative risk, 1.24; 95% CI, 1.18-1.30).²

Another meta-analysis included 6 cohort studies involving more than 1 million pregnancies and 3 case-control studies involving 2530 stillbirths and 2837 controls from 1980-2005. There was an association between increasing BMI and stillbirth: the odds ratio (OR) was 1.47 (95% CI, 1.08-1.94) for those with a BMI of 25.0 to 29.9 and 2.07 (95% CI, 1.59-2.74) for those with a BMI ≥ 30.0, compared to those with a normal BMI.³

However, a retrospective cohort study of 182,362 singleton births including 442 stillbirths found no association between stillbirth and increasing BMI. The OR was 1.10 (95% CI, 0.90-1.36) for those with a BMI of 25.0 to 29.9 and 1.09 (95% CI, 0.87-1.37) for those with a BMI ≥ 30.0, compared to those with a normal BMI.⁴ However, this cohort study may have been underpowered to detect an association between stillbirth and BMI.

Recommendations from others

In 2021, ACOG suggested that weekly antenatal testing may be considered from 34w0d for pregnant people with a BMI ≥ 40.0 and from 37w0d for pregnant people with a BMI between 35.0 and 39.9.⁵ The 2021 ACOG Practice Bulletin on Obesity in Pregnancy rates this recommendation as Level C—based primarily on consensus and expert opinion.⁶

A 2018 Royal College of Obstetricians and Gynecologists Green-top Guideline recognizes “definitive recommendations for fetal surveillance are hampered by the lack of randomized controlled trials demonstrating that antepartum fetal surveillance decreases perinatal morbidity or mortality in late-term and post-term gestations…. There are no definitive studies determining the optimal type or frequency of such testing and no evidence specific for women with obesity.”⁷

A 2019 Society of Obstetricians and Gynecologists of Canada practice guideline states “stillbirth is more common with maternal obesity” and recommends “increased fetal surveillance … in the third trimester if reduced fetal movements are reported.” The guideline notes “the role for non-stress tests … in surveillance of well-being in this population is uncertain.” Also, for pregnant people with a BMI > 30, “assessment of fetal well-being is … recommended weekly from 37 weeks until delivery.” Finally, increased fetal surveillance is recommended in the setting of increased BMI and an abnormal pulsatility index of the umbilical artery and/or maternal uterine artery.⁸

Editor’s takeaway

Evidence demonstrates that increased maternal BMI is associated with increased stillbirths. However, evidence has not shown that third-trimester antenatal testing decreases this morbidity and mortality. Expert opinion varies, with ACOG recommending weekly antenatal testing from 34 and 37 weeks for pregnant people with a BMI ≥ 40 and of 35 to 39.9, respectively.

Evidence summary

Early evidence suggested benefit from IM progesterone

A 2003 RCT compared weekly IM progesterone (n = 310) and placebo (n = 153) injections in women with a history of spontaneous preterm delivery. Participants were at 15w0d to 20w3d of a singleton pregnancy with no fetal abnormality. The 17-OHP group, compared to the placebo group, had significantly fewer deliveries at < 37 weeks (36.3% vs 54.9%; relative risk [RR] = 0.66; 95% CI, 0.54 to 0.81; number needed to treat [NNT] = 6), at < 35 weeks (20.6% vs 30.7%; RR = 0.67; 95% CI, 0.48 to 0.93; NNT = 10), and at < 32 weeks (11.4% vs 19.6%; RR = 0.58; 95% CI, 0.37 to 0.91; NNT = 13).¹ There were significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen in infants of women in the treatment group.¹ The study was underpowered to detect neonatal morbidity.

A 2013 Cochrane Review (5 studies including the 2003 RCT; 602 women) found that 17-OHP led to a decreased risk of birth at < 34 weeks (RR = 0.31; 95% CI, 0.14-0.69). It also led to a significant reduction in perinatal and neonatal mortality, birth at < 37 weeks, birthweight < 2500 g, use of assisted ventilation, incidence of necrotizing enterocolitis, and admission to the neonatal ICU.²

In a large follow-up study, progesterone did not demonstrate benefit

The PROLONG study was a double-blind, placebo-controlled international RCT of women with a previous singleton spontaneous preterm birth. The study involved 93 clinical centers in 9 countries: 41 in the United States and 52 outside the United States. The ­PROLONG study was much larger than the 2003 study: 1139 active treatment (vs 310) and 578 placebo (vs 153) participants. Women were randomized 2:1 to receive either 250 mg 17-OHP or inert oil placebo weekly from 16w0d-20w6d until 36 weeks. The outcome measures were: (1) delivery at < 35 weeks and (2) a neonatal morbidity composite index. This composite index included any of the following: neonatal death, grade 3 or 4 intraventricular hemorrhage, respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, and proven sepsis.³

Our best evidence does not support routine IM progesterone use to prevent preterm delivery.

Progesterone did not improve any of the studied outcomes: there were no significant differences in the frequency of birth at < 35 weeks (17-OHP 11% vs placebo 11.5%; RR = 0.95; 95% CI, 0.71-1.26), in neonatal morbidity index (17-OHP 5.6% vs placebo 5%; RR = 1.12; 95% CI, 0.68-1.61), and in frequency of fetal/early infant death (17-OHP 1.7% vs placebo 1.9%; RR = 0.87; 95% CI, 0.4-1.81).³ In the United States subgroup (n = 391; 23% of all patients), there was no significant difference in rate of birth at < 35 weeks (17-OHP 15.6% vs placebo 17.6%; RR = 0.88; 95% CI, 0.55-1.40).³

However, PROLONG had some limitations. Importantly, the 2003 RCT included 183 (59%) non-Hispanic Black women in the experimental group and 90 (58.5%) in the control group, whereas the 2020 PROLONG study had only 6.6% non-Hispanic Black participants. The neonatal outcome data for the PROLONG study only included 6 Black women in the experimental arm and 3 in the control arm.^3,4 Black women have prematurity rates that are 2 to 3 times higher than those in White women.⁵

Additionally, the PROLONG study had fewer smokers and more women who were married/living with a partner. Compared with prior studies, the PROLONG study had a lower proportion of women with > 1 spontaneous preterm birth and fewer with a shortened cervix (< 2%).³ As a result of having lower risk participants, PROLONG may have been underpowered to detect improvements in outcome.³

A subsequent meta-analysis suggests some benefit for high-risk women

The 2021 Evaluating Progestogens for Preventing Preterm birth International Collaborative (EPPPIC) meta-analysis of individual data from 31 RCTs—involving 11,644 women and 16,185 babies—found that, compared with placebo, 17-OHP for women with a history of preterm delivery or short cervix did not significantly decrease the number of babies born before 34 weeks (5 trials [including the 2003 RCT and PROLONG studies]; 3053 women; RR = 0.83; 95% CI, 0.68–1.01).⁶ However, it found that vaginal progesterone significantly decreased birth prior to 34 weeks (9 trials; 3769 women; RR = 0.78, 95% CI, 0.68-0.90).⁶ The authors concluded that both IM and vaginal progesterone decreased preterm delivery in high-risk women. The effect was stronger for women with a short cervix than for women with a history of preterm delivery.⁶

Continue to: Recommendations from others

In 2008, a joint ACOG/SMFM statement said, “Progesterone supplementation for the prevention of recurrent preterm birth should be offered to women with a singleton pregnancy and prior spontaneous preterm birth.”⁷ A 2012 ACOG Practice Bulletin stated that, “A woman with a singleton gestation and a prior spontaneous preterm singleton birth should be offered progesterone supplementation starting at 16 to 24 weeks of gestation, regardless of transvaginal ultrasound cervical length, to reduce the risk of recurrent spontaneous preterm birth.”⁸

In 2011, Makena (hydroxyprogesterone caproate injection) received accelerated approval from the FDA. In October 2020, the FDA Advisory Committee recommended that Makena be withdrawn from the market (9 to 7 vote).⁹ On October 5, 2020, the FDA’s Center for Drug Evaluation and Research (CDER) proposed that Makena be withdrawn from the market “because the required postmarket study failed to verify clinical benefit and we have concluded that the available evidence does not show Makena is effective for its approved use.”¹⁰ A subgroup analysis by CDER did not find benefit for any subgroup, including high-risk women.¹⁰ However, Makena will remain on the market unless its manufacturer withdraws it or the FDA Commissioner mandates its removal.

In response to the FDA’s proposal, both ACOG and SMFM recommended that “obstetric health care professionals discuss Makena’s benefits, risks, and uncertainties with their patients”¹¹ as part of “a shared ­decision-making approach, taking into account the lack of short-term safety concerns but uncertainty regarding benefit.”¹² Both organizations reiterated their position on shared decision-making after the EPPPIC meta-analysis was published.¹³

Studies comparing the 2 routes of administration (vaginal and IM) are underway.¹³

Editor’s takeaway

Our best evidence does not support routine IM progesterone use to prevent preterm delivery. However, therapeutic inertia, uncertainty, and defensive medicine may slow down adoption of this newer evidence. Shared decision-making can assist treatment decisions, but it is not a substitute for following the best evidence.

Evidence summary

Early evidence suggested benefit from IM progesterone

A 2003 RCT compared weekly IM progesterone (n = 310) and placebo (n = 153) injections in women with a history of spontaneous preterm delivery. Participants were at 15w0d to 20w3d of a singleton pregnancy with no fetal abnormality. The 17-OHP group, compared to the placebo group, had significantly fewer deliveries at < 37 weeks (36.3% vs 54.9%; relative risk [RR] = 0.66; 95% CI, 0.54 to 0.81; number needed to treat [NNT] = 6), at < 35 weeks (20.6% vs 30.7%; RR = 0.67; 95% CI, 0.48 to 0.93; NNT = 10), and at < 32 weeks (11.4% vs 19.6%; RR = 0.58; 95% CI, 0.37 to 0.91; NNT = 13).¹ There were significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen in infants of women in the treatment group.¹ The study was underpowered to detect neonatal morbidity.

A 2013 Cochrane Review (5 studies including the 2003 RCT; 602 women) found that 17-OHP led to a decreased risk of birth at < 34 weeks (RR = 0.31; 95% CI, 0.14-0.69). It also led to a significant reduction in perinatal and neonatal mortality, birth at < 37 weeks, birthweight < 2500 g, use of assisted ventilation, incidence of necrotizing enterocolitis, and admission to the neonatal ICU.²

In a large follow-up study, progesterone did not demonstrate benefit

The PROLONG study was a double-blind, placebo-controlled international RCT of women with a previous singleton spontaneous preterm birth. The study involved 93 clinical centers in 9 countries: 41 in the United States and 52 outside the United States. The ­PROLONG study was much larger than the 2003 study: 1139 active treatment (vs 310) and 578 placebo (vs 153) participants. Women were randomized 2:1 to receive either 250 mg 17-OHP or inert oil placebo weekly from 16w0d-20w6d until 36 weeks. The outcome measures were: (1) delivery at < 35 weeks and (2) a neonatal morbidity composite index. This composite index included any of the following: neonatal death, grade 3 or 4 intraventricular hemorrhage, respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, and proven sepsis.³

Our best evidence does not support routine IM progesterone use to prevent preterm delivery.

Progesterone did not improve any of the studied outcomes: there were no significant differences in the frequency of birth at < 35 weeks (17-OHP 11% vs placebo 11.5%; RR = 0.95; 95% CI, 0.71-1.26), in neonatal morbidity index (17-OHP 5.6% vs placebo 5%; RR = 1.12; 95% CI, 0.68-1.61), and in frequency of fetal/early infant death (17-OHP 1.7% vs placebo 1.9%; RR = 0.87; 95% CI, 0.4-1.81).³ In the United States subgroup (n = 391; 23% of all patients), there was no significant difference in rate of birth at < 35 weeks (17-OHP 15.6% vs placebo 17.6%; RR = 0.88; 95% CI, 0.55-1.40).³

However, PROLONG had some limitations. Importantly, the 2003 RCT included 183 (59%) non-Hispanic Black women in the experimental group and 90 (58.5%) in the control group, whereas the 2020 PROLONG study had only 6.6% non-Hispanic Black participants. The neonatal outcome data for the PROLONG study only included 6 Black women in the experimental arm and 3 in the control arm.^3,4 Black women have prematurity rates that are 2 to 3 times higher than those in White women.⁵

Additionally, the PROLONG study had fewer smokers and more women who were married/living with a partner. Compared with prior studies, the PROLONG study had a lower proportion of women with > 1 spontaneous preterm birth and fewer with a shortened cervix (< 2%).³ As a result of having lower risk participants, PROLONG may have been underpowered to detect improvements in outcome.³

A subsequent meta-analysis suggests some benefit for high-risk women

The 2021 Evaluating Progestogens for Preventing Preterm birth International Collaborative (EPPPIC) meta-analysis of individual data from 31 RCTs—involving 11,644 women and 16,185 babies—found that, compared with placebo, 17-OHP for women with a history of preterm delivery or short cervix did not significantly decrease the number of babies born before 34 weeks (5 trials [including the 2003 RCT and PROLONG studies]; 3053 women; RR = 0.83; 95% CI, 0.68–1.01).⁶ However, it found that vaginal progesterone significantly decreased birth prior to 34 weeks (9 trials; 3769 women; RR = 0.78, 95% CI, 0.68-0.90).⁶ The authors concluded that both IM and vaginal progesterone decreased preterm delivery in high-risk women. The effect was stronger for women with a short cervix than for women with a history of preterm delivery.⁶

Continue to: Recommendations from others

In 2008, a joint ACOG/SMFM statement said, “Progesterone supplementation for the prevention of recurrent preterm birth should be offered to women with a singleton pregnancy and prior spontaneous preterm birth.”⁷ A 2012 ACOG Practice Bulletin stated that, “A woman with a singleton gestation and a prior spontaneous preterm singleton birth should be offered progesterone supplementation starting at 16 to 24 weeks of gestation, regardless of transvaginal ultrasound cervical length, to reduce the risk of recurrent spontaneous preterm birth.”⁸

In 2011, Makena (hydroxyprogesterone caproate injection) received accelerated approval from the FDA. In October 2020, the FDA Advisory Committee recommended that Makena be withdrawn from the market (9 to 7 vote).⁹ On October 5, 2020, the FDA’s Center for Drug Evaluation and Research (CDER) proposed that Makena be withdrawn from the market “because the required postmarket study failed to verify clinical benefit and we have concluded that the available evidence does not show Makena is effective for its approved use.”¹⁰ A subgroup analysis by CDER did not find benefit for any subgroup, including high-risk women.¹⁰ However, Makena will remain on the market unless its manufacturer withdraws it or the FDA Commissioner mandates its removal.

In response to the FDA’s proposal, both ACOG and SMFM recommended that “obstetric health care professionals discuss Makena’s benefits, risks, and uncertainties with their patients”¹¹ as part of “a shared ­decision-making approach, taking into account the lack of short-term safety concerns but uncertainty regarding benefit.”¹² Both organizations reiterated their position on shared decision-making after the EPPPIC meta-analysis was published.¹³

Studies comparing the 2 routes of administration (vaginal and IM) are underway.¹³

Editor’s takeaway

Our best evidence does not support routine IM progesterone use to prevent preterm delivery. However, therapeutic inertia, uncertainty, and defensive medicine may slow down adoption of this newer evidence. Shared decision-making can assist treatment decisions, but it is not a substitute for following the best evidence.

Evidence summary

Early evidence suggested benefit from IM progesterone

A 2003 RCT compared weekly IM progesterone (n = 310) and placebo (n = 153) injections in women with a history of spontaneous preterm delivery. Participants were at 15w0d to 20w3d of a singleton pregnancy with no fetal abnormality. The 17-OHP group, compared to the placebo group, had significantly fewer deliveries at < 37 weeks (36.3% vs 54.9%; relative risk [RR] = 0.66; 95% CI, 0.54 to 0.81; number needed to treat [NNT] = 6), at < 35 weeks (20.6% vs 30.7%; RR = 0.67; 95% CI, 0.48 to 0.93; NNT = 10), and at < 32 weeks (11.4% vs 19.6%; RR = 0.58; 95% CI, 0.37 to 0.91; NNT = 13).¹ There were significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen in infants of women in the treatment group.¹ The study was underpowered to detect neonatal morbidity.

A 2013 Cochrane Review (5 studies including the 2003 RCT; 602 women) found that 17-OHP led to a decreased risk of birth at < 34 weeks (RR = 0.31; 95% CI, 0.14-0.69). It also led to a significant reduction in perinatal and neonatal mortality, birth at < 37 weeks, birthweight < 2500 g, use of assisted ventilation, incidence of necrotizing enterocolitis, and admission to the neonatal ICU.²

In a large follow-up study, progesterone did not demonstrate benefit

The PROLONG study was a double-blind, placebo-controlled international RCT of women with a previous singleton spontaneous preterm birth. The study involved 93 clinical centers in 9 countries: 41 in the United States and 52 outside the United States. The ­PROLONG study was much larger than the 2003 study: 1139 active treatment (vs 310) and 578 placebo (vs 153) participants. Women were randomized 2:1 to receive either 250 mg 17-OHP or inert oil placebo weekly from 16w0d-20w6d until 36 weeks. The outcome measures were: (1) delivery at < 35 weeks and (2) a neonatal morbidity composite index. This composite index included any of the following: neonatal death, grade 3 or 4 intraventricular hemorrhage, respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, and proven sepsis.³

Our best evidence does not support routine IM progesterone use to prevent preterm delivery.

Progesterone did not improve any of the studied outcomes: there were no significant differences in the frequency of birth at < 35 weeks (17-OHP 11% vs placebo 11.5%; RR = 0.95; 95% CI, 0.71-1.26), in neonatal morbidity index (17-OHP 5.6% vs placebo 5%; RR = 1.12; 95% CI, 0.68-1.61), and in frequency of fetal/early infant death (17-OHP 1.7% vs placebo 1.9%; RR = 0.87; 95% CI, 0.4-1.81).³ In the United States subgroup (n = 391; 23% of all patients), there was no significant difference in rate of birth at < 35 weeks (17-OHP 15.6% vs placebo 17.6%; RR = 0.88; 95% CI, 0.55-1.40).³

However, PROLONG had some limitations. Importantly, the 2003 RCT included 183 (59%) non-Hispanic Black women in the experimental group and 90 (58.5%) in the control group, whereas the 2020 PROLONG study had only 6.6% non-Hispanic Black participants. The neonatal outcome data for the PROLONG study only included 6 Black women in the experimental arm and 3 in the control arm.^3,4 Black women have prematurity rates that are 2 to 3 times higher than those in White women.⁵

Additionally, the PROLONG study had fewer smokers and more women who were married/living with a partner. Compared with prior studies, the PROLONG study had a lower proportion of women with > 1 spontaneous preterm birth and fewer with a shortened cervix (< 2%).³ As a result of having lower risk participants, PROLONG may have been underpowered to detect improvements in outcome.³

A subsequent meta-analysis suggests some benefit for high-risk women

The 2021 Evaluating Progestogens for Preventing Preterm birth International Collaborative (EPPPIC) meta-analysis of individual data from 31 RCTs—involving 11,644 women and 16,185 babies—found that, compared with placebo, 17-OHP for women with a history of preterm delivery or short cervix did not significantly decrease the number of babies born before 34 weeks (5 trials [including the 2003 RCT and PROLONG studies]; 3053 women; RR = 0.83; 95% CI, 0.68–1.01).⁶ However, it found that vaginal progesterone significantly decreased birth prior to 34 weeks (9 trials; 3769 women; RR = 0.78, 95% CI, 0.68-0.90).⁶ The authors concluded that both IM and vaginal progesterone decreased preterm delivery in high-risk women. The effect was stronger for women with a short cervix than for women with a history of preterm delivery.⁶

Continue to: Recommendations from others

In 2008, a joint ACOG/SMFM statement said, “Progesterone supplementation for the prevention of recurrent preterm birth should be offered to women with a singleton pregnancy and prior spontaneous preterm birth.”⁷ A 2012 ACOG Practice Bulletin stated that, “A woman with a singleton gestation and a prior spontaneous preterm singleton birth should be offered progesterone supplementation starting at 16 to 24 weeks of gestation, regardless of transvaginal ultrasound cervical length, to reduce the risk of recurrent spontaneous preterm birth.”⁸

In 2011, Makena (hydroxyprogesterone caproate injection) received accelerated approval from the FDA. In October 2020, the FDA Advisory Committee recommended that Makena be withdrawn from the market (9 to 7 vote).⁹ On October 5, 2020, the FDA’s Center for Drug Evaluation and Research (CDER) proposed that Makena be withdrawn from the market “because the required postmarket study failed to verify clinical benefit and we have concluded that the available evidence does not show Makena is effective for its approved use.”¹⁰ A subgroup analysis by CDER did not find benefit for any subgroup, including high-risk women.¹⁰ However, Makena will remain on the market unless its manufacturer withdraws it or the FDA Commissioner mandates its removal.

In response to the FDA’s proposal, both ACOG and SMFM recommended that “obstetric health care professionals discuss Makena’s benefits, risks, and uncertainties with their patients”¹¹ as part of “a shared ­decision-making approach, taking into account the lack of short-term safety concerns but uncertainty regarding benefit.”¹² Both organizations reiterated their position on shared decision-making after the EPPPIC meta-analysis was published.¹³

Studies comparing the 2 routes of administration (vaginal and IM) are underway.¹³

Editor’s takeaway

Our best evidence does not support routine IM progesterone use to prevent preterm delivery. However, therapeutic inertia, uncertainty, and defensive medicine may slow down adoption of this newer evidence. Shared decision-making can assist treatment decisions, but it is not a substitute for following the best evidence.

EVIDENCE SUMMARY

Mixed results, quality issues do not support screening asymptomatic patients

A meta-analysis (12 observational studies; n = 1002) compared the diagnostic accuracy of panoramic radiography (PR) to Doppler ultrasonography (11 studies) or angiography (1 study) in detecting calcified carotid artery atheroma (CCAA).¹ The studies, conducted in 8 countries, were published after 2006. Patients were 29 to 71 years old without history of stroke, endarterectomy, angioplasty, or renal disease. In a pooled analysis, the sensitivity of PR to detect CCAA was 73% (range, 31%-95%; 95% CI, 69%-77%), and the specificity was 72% (range, 19%-99%; 95% CI, 68%-76%). The pooled positive predictive value was 70% (range, 37%-95%; 95% CI, 66%-74%), and negative predictive value was 75% (range, 43%-93%; 95% CI, 71%-79%). Pooled positive likelihood ratio was 2.32 (95% CI, 1.49-3.60) and negative likelihood ratio was 0.40 (95% CI, 0.25-0.63). Seven studies had high risk of patient selection bias, and most had methodologic limitations.

In a retrospective cohort study (n = 778) from the United States, researchers identified carotid artery calcifications on routine dental radiographs in patients ≥ 55 years old and prospectively performed duplex ultrasound (DUS) to assess for significant carotid stenosis (≥ 50%).² Twenty-seven patients (3.5%) had carotid artery calcifications on radiographs, and 20 of those patients underwent DUS of bilateral carotid arteries (40 sides). Of 26 sides with calcifications on radiograph, 13 (50%) had stenosis confirmed with DUS. Of the 14 sides without calcification on radiograph, 3 (21%) had stenosis on DUS. The positive predictive value for calcification on PR predicting significant carotid stenosis was between 40% and 80%.

In a cross-sectional study from Sweden, investigators sought surgical candidates for asymptomatic carotid endarterectomy and performed PRs of 1182 patients.³ Calcifications were found in 176 people; 117 of them were eligible for asymptomatic carotid endarterectomy (ages 18-74; no cancer or other serious comorbidity; and no prior stroke or transient ischemic attack) and underwent ultrasound to assess for significant carotid stenosis (≥ 50%). Of the 117 participants who underwent ultrasound, 8 (6.8%; 95% CI, 2.2%-11.5%), all men, were found to have significant carotid stenosis. Compared to a sex- and age-matched reference group (n = 119) with no calcifications on PR, the prevalence of carotid stenosis was significantly higher in men (12.5%; 95% CI, 4.2%-20.8%) and in patients who were current smokers (19%; 95% CI, 0.7%-37.4%), were taking cholesterol medications (13.1%; 95% CI 4.4%-21.8%), and had a cardiovascular event history (15.9%; 95% CI, 7%-27.2%).

Recommendations from others

The US Preventive Services Task Force ­(USPSTF) and the American Academy of Family Physicians do not mention carotid screening with radiographs but recommend against screening for carotid artery stenosis in asymptomatic adults because the risks of screening outweigh the potential benefits (USPSTF grade D; the harms outweigh the benefits).^4,5

Editor’s takeaway

If you see calcification of the carotid artery on an x-ray of an asymptomatic patient, ignore it. The positive and negative predictive values for carotid stenosis are poor, and you should not pursue further testing.

EVIDENCE SUMMARY

Mixed results, quality issues do not support screening asymptomatic patients

A meta-analysis (12 observational studies; n = 1002) compared the diagnostic accuracy of panoramic radiography (PR) to Doppler ultrasonography (11 studies) or angiography (1 study) in detecting calcified carotid artery atheroma (CCAA).¹ The studies, conducted in 8 countries, were published after 2006. Patients were 29 to 71 years old without history of stroke, endarterectomy, angioplasty, or renal disease. In a pooled analysis, the sensitivity of PR to detect CCAA was 73% (range, 31%-95%; 95% CI, 69%-77%), and the specificity was 72% (range, 19%-99%; 95% CI, 68%-76%). The pooled positive predictive value was 70% (range, 37%-95%; 95% CI, 66%-74%), and negative predictive value was 75% (range, 43%-93%; 95% CI, 71%-79%). Pooled positive likelihood ratio was 2.32 (95% CI, 1.49-3.60) and negative likelihood ratio was 0.40 (95% CI, 0.25-0.63). Seven studies had high risk of patient selection bias, and most had methodologic limitations.

In a retrospective cohort study (n = 778) from the United States, researchers identified carotid artery calcifications on routine dental radiographs in patients ≥ 55 years old and prospectively performed duplex ultrasound (DUS) to assess for significant carotid stenosis (≥ 50%).² Twenty-seven patients (3.5%) had carotid artery calcifications on radiographs, and 20 of those patients underwent DUS of bilateral carotid arteries (40 sides). Of 26 sides with calcifications on radiograph, 13 (50%) had stenosis confirmed with DUS. Of the 14 sides without calcification on radiograph, 3 (21%) had stenosis on DUS. The positive predictive value for calcification on PR predicting significant carotid stenosis was between 40% and 80%.

In a cross-sectional study from Sweden, investigators sought surgical candidates for asymptomatic carotid endarterectomy and performed PRs of 1182 patients.³ Calcifications were found in 176 people; 117 of them were eligible for asymptomatic carotid endarterectomy (ages 18-74; no cancer or other serious comorbidity; and no prior stroke or transient ischemic attack) and underwent ultrasound to assess for significant carotid stenosis (≥ 50%). Of the 117 participants who underwent ultrasound, 8 (6.8%; 95% CI, 2.2%-11.5%), all men, were found to have significant carotid stenosis. Compared to a sex- and age-matched reference group (n = 119) with no calcifications on PR, the prevalence of carotid stenosis was significantly higher in men (12.5%; 95% CI, 4.2%-20.8%) and in patients who were current smokers (19%; 95% CI, 0.7%-37.4%), were taking cholesterol medications (13.1%; 95% CI 4.4%-21.8%), and had a cardiovascular event history (15.9%; 95% CI, 7%-27.2%).

Recommendations from others

The US Preventive Services Task Force ­(USPSTF) and the American Academy of Family Physicians do not mention carotid screening with radiographs but recommend against screening for carotid artery stenosis in asymptomatic adults because the risks of screening outweigh the potential benefits (USPSTF grade D; the harms outweigh the benefits).^4,5

Editor’s takeaway

If you see calcification of the carotid artery on an x-ray of an asymptomatic patient, ignore it. The positive and negative predictive values for carotid stenosis are poor, and you should not pursue further testing.

EVIDENCE SUMMARY

Mixed results, quality issues do not support screening asymptomatic patients

A meta-analysis (12 observational studies; n = 1002) compared the diagnostic accuracy of panoramic radiography (PR) to Doppler ultrasonography (11 studies) or angiography (1 study) in detecting calcified carotid artery atheroma (CCAA).¹ The studies, conducted in 8 countries, were published after 2006. Patients were 29 to 71 years old without history of stroke, endarterectomy, angioplasty, or renal disease. In a pooled analysis, the sensitivity of PR to detect CCAA was 73% (range, 31%-95%; 95% CI, 69%-77%), and the specificity was 72% (range, 19%-99%; 95% CI, 68%-76%). The pooled positive predictive value was 70% (range, 37%-95%; 95% CI, 66%-74%), and negative predictive value was 75% (range, 43%-93%; 95% CI, 71%-79%). Pooled positive likelihood ratio was 2.32 (95% CI, 1.49-3.60) and negative likelihood ratio was 0.40 (95% CI, 0.25-0.63). Seven studies had high risk of patient selection bias, and most had methodologic limitations.

In a retrospective cohort study (n = 778) from the United States, researchers identified carotid artery calcifications on routine dental radiographs in patients ≥ 55 years old and prospectively performed duplex ultrasound (DUS) to assess for significant carotid stenosis (≥ 50%).² Twenty-seven patients (3.5%) had carotid artery calcifications on radiographs, and 20 of those patients underwent DUS of bilateral carotid arteries (40 sides). Of 26 sides with calcifications on radiograph, 13 (50%) had stenosis confirmed with DUS. Of the 14 sides without calcification on radiograph, 3 (21%) had stenosis on DUS. The positive predictive value for calcification on PR predicting significant carotid stenosis was between 40% and 80%.

In a cross-sectional study from Sweden, investigators sought surgical candidates for asymptomatic carotid endarterectomy and performed PRs of 1182 patients.³ Calcifications were found in 176 people; 117 of them were eligible for asymptomatic carotid endarterectomy (ages 18-74; no cancer or other serious comorbidity; and no prior stroke or transient ischemic attack) and underwent ultrasound to assess for significant carotid stenosis (≥ 50%). Of the 117 participants who underwent ultrasound, 8 (6.8%; 95% CI, 2.2%-11.5%), all men, were found to have significant carotid stenosis. Compared to a sex- and age-matched reference group (n = 119) with no calcifications on PR, the prevalence of carotid stenosis was significantly higher in men (12.5%; 95% CI, 4.2%-20.8%) and in patients who were current smokers (19%; 95% CI, 0.7%-37.4%), were taking cholesterol medications (13.1%; 95% CI 4.4%-21.8%), and had a cardiovascular event history (15.9%; 95% CI, 7%-27.2%).

Recommendations from others

The US Preventive Services Task Force ­(USPSTF) and the American Academy of Family Physicians do not mention carotid screening with radiographs but recommend against screening for carotid artery stenosis in asymptomatic adults because the risks of screening outweigh the potential benefits (USPSTF grade D; the harms outweigh the benefits).^4,5

Editor’s takeaway

If you see calcification of the carotid artery on an x-ray of an asymptomatic patient, ignore it. The positive and negative predictive values for carotid stenosis are poor, and you should not pursue further testing.

EVIDENCE SUMMARY

A 2017 double-blind RCT that included 20,060 women with PPH from 21 countries (the WOMAN trial) found that the risk of maternal mortality was significantly lower among women who received tranexamic acid as part of their PPH treatment compared with placebo (1.5% [N = 155] vs 1.9% [N = 191]; P = .045; relative risk [RR] = 0.81; 95% confidence interval [CI], 0.65-1; number needed to treat [NNT] = 250).¹

Inclusion criteria were age 16 years or older, postpartum course complicated by hemorrhage of known or unknown etiology, and a case in which the clinician considered using tranexamic acid in addition to the standard of care. PPH was defined as > 500 mL blood loss after vaginal delivery, > 1000 mL blood loss after cesarean section, or blood loss sufficient to produce hemodynamic compromise.

Researchers randomized 10,051 women to the tranexamic acid group and 10,009 to the placebo group. Women in the experimental group received a 1-g IV injection of tranexamic acid over 10 to 20 minutes. A second dose was given if bleeding restarted after 30 minutes and within 24 hours of the first dose.

To reduce mortality give tranexamic acid promptly

Tranexamic acid reduced mortality most effectively compared with placebo when given within 3 hours of delivery (1.2% [N = 89] vs 1.7% [N = 127]; P = .008; RR = 0.69; 95% CI 0.52-0.91; NNT = 200). After 3 hours, no significant decrease in mortality occurred. No significant difference in effect was noted between vaginal and cesarean deliveries nor between uterine atony as the primary cause of hemorrhage and other causes.

Administering tranexamic acid didn’t reduce the composite primary endpoint of hysterectomy or death from all causes. Nor did it reduce the secondary endpoints of intrauterine tamponade, embolization, manual placental extraction, arterial ligation, blood transfusions, or number of units of packed red blood cells. The tranexamic acid group showed a significant decrease in cases of laparotomy for PPH (0.8% vs 1.3%; P = .002; RR = 0.64; 95% CI, 0.49-0.85; NNT = 200).

Women who received tranexamic acid vs placebo showed no significant difference in mortality from pulmonary embolism (0.1% [N = 10] vs 0.1% [N = 11]; P = .82; RR = .9; 95% CI, 0.38-2.13), organ failure ure (0.3% [N = 25] vs 0.2% [N = 18]; P = .29; RR = 1.38; 95% CI, 0.75-2.53), sepsis (0.2% [N = 15] vs 0.1% [N = 8]; P = .15; RR = 1.87; 95% CI, 0.79-4.4), eclampsia (0.02% [N = 2] vs 0.1% [N = 8]; P = .057; RR = .25; 95% CI, 0.05-1.17), or other causes (0.2% [N = 20] vs 0.2% [N = 20]; P = .99; RR = 0.99; 95% CI, 0.54-1.85).

Tranexamic acid doesn’t increase the risk of thromboembolism

A 2018 Cochrane review sought more broadly to determine the general effectiveness and safety of antifibrinolytic drugs in treating primary PPH.² Of 15 RCTs identified, only 3 met the inclusion criteria for the review, 1 of which was the WOMAN trial (which contributed most of the data in the review). The other trials were a study conducted in France that recruited 152 women and a study of 200 women in Iran that contributed only 1 primary outcome—estimated blood loss—to the review. The former study didn’t report any maternal deaths, and the latter study didn’t look at maternal deaths. The Cochrane review concluded, based on data from the WOMAN trial, that IV tranexamic acid, if given as early as possible, reduced mortality from bleeding in women with primary PPH after both vaginal and cesarean delivery and didn’t increase the risk of thromboembolic events.²

Continue to: RECOMMENDATIONS

The newest practice guidelines on the management of postpartum hemorrhage published by the American College of Obstetricians and Gynecologists recommends considering tranexamic acid as an additional agent in managing PPH when initial standard-of-care treatments fail.³

Editor’s takeaway

The large international double-blind, randomized placebo-controlled trial provides convincing evidence that tranexamic acid should be administered readily in cases of PPH.

EVIDENCE SUMMARY

A 2017 double-blind RCT that included 20,060 women with PPH from 21 countries (the WOMAN trial) found that the risk of maternal mortality was significantly lower among women who received tranexamic acid as part of their PPH treatment compared with placebo (1.5% [N = 155] vs 1.9% [N = 191]; P = .045; relative risk [RR] = 0.81; 95% confidence interval [CI], 0.65-1; number needed to treat [NNT] = 250).¹

Inclusion criteria were age 16 years or older, postpartum course complicated by hemorrhage of known or unknown etiology, and a case in which the clinician considered using tranexamic acid in addition to the standard of care. PPH was defined as > 500 mL blood loss after vaginal delivery, > 1000 mL blood loss after cesarean section, or blood loss sufficient to produce hemodynamic compromise.

Researchers randomized 10,051 women to the tranexamic acid group and 10,009 to the placebo group. Women in the experimental group received a 1-g IV injection of tranexamic acid over 10 to 20 minutes. A second dose was given if bleeding restarted after 30 minutes and within 24 hours of the first dose.

To reduce mortality give tranexamic acid promptly

Tranexamic acid reduced mortality most effectively compared with placebo when given within 3 hours of delivery (1.2% [N = 89] vs 1.7% [N = 127]; P = .008; RR = 0.69; 95% CI 0.52-0.91; NNT = 200). After 3 hours, no significant decrease in mortality occurred. No significant difference in effect was noted between vaginal and cesarean deliveries nor between uterine atony as the primary cause of hemorrhage and other causes.

Administering tranexamic acid didn’t reduce the composite primary endpoint of hysterectomy or death from all causes. Nor did it reduce the secondary endpoints of intrauterine tamponade, embolization, manual placental extraction, arterial ligation, blood transfusions, or number of units of packed red blood cells. The tranexamic acid group showed a significant decrease in cases of laparotomy for PPH (0.8% vs 1.3%; P = .002; RR = 0.64; 95% CI, 0.49-0.85; NNT = 200).

Women who received tranexamic acid vs placebo showed no significant difference in mortality from pulmonary embolism (0.1% [N = 10] vs 0.1% [N = 11]; P = .82; RR = .9; 95% CI, 0.38-2.13), organ failure ure (0.3% [N = 25] vs 0.2% [N = 18]; P = .29; RR = 1.38; 95% CI, 0.75-2.53), sepsis (0.2% [N = 15] vs 0.1% [N = 8]; P = .15; RR = 1.87; 95% CI, 0.79-4.4), eclampsia (0.02% [N = 2] vs 0.1% [N = 8]; P = .057; RR = .25; 95% CI, 0.05-1.17), or other causes (0.2% [N = 20] vs 0.2% [N = 20]; P = .99; RR = 0.99; 95% CI, 0.54-1.85).

Tranexamic acid doesn’t increase the risk of thromboembolism

A 2018 Cochrane review sought more broadly to determine the general effectiveness and safety of antifibrinolytic drugs in treating primary PPH.² Of 15 RCTs identified, only 3 met the inclusion criteria for the review, 1 of which was the WOMAN trial (which contributed most of the data in the review). The other trials were a study conducted in France that recruited 152 women and a study of 200 women in Iran that contributed only 1 primary outcome—estimated blood loss—to the review. The former study didn’t report any maternal deaths, and the latter study didn’t look at maternal deaths. The Cochrane review concluded, based on data from the WOMAN trial, that IV tranexamic acid, if given as early as possible, reduced mortality from bleeding in women with primary PPH after both vaginal and cesarean delivery and didn’t increase the risk of thromboembolic events.²

Continue to: RECOMMENDATIONS

The newest practice guidelines on the management of postpartum hemorrhage published by the American College of Obstetricians and Gynecologists recommends considering tranexamic acid as an additional agent in managing PPH when initial standard-of-care treatments fail.³

Editor’s takeaway

The large international double-blind, randomized placebo-controlled trial provides convincing evidence that tranexamic acid should be administered readily in cases of PPH.

EVIDENCE SUMMARY

A 2017 double-blind RCT that included 20,060 women with PPH from 21 countries (the WOMAN trial) found that the risk of maternal mortality was significantly lower among women who received tranexamic acid as part of their PPH treatment compared with placebo (1.5% [N = 155] vs 1.9% [N = 191]; P = .045; relative risk [RR] = 0.81; 95% confidence interval [CI], 0.65-1; number needed to treat [NNT] = 250).¹

Inclusion criteria were age 16 years or older, postpartum course complicated by hemorrhage of known or unknown etiology, and a case in which the clinician considered using tranexamic acid in addition to the standard of care. PPH was defined as > 500 mL blood loss after vaginal delivery, > 1000 mL blood loss after cesarean section, or blood loss sufficient to produce hemodynamic compromise.

Researchers randomized 10,051 women to the tranexamic acid group and 10,009 to the placebo group. Women in the experimental group received a 1-g IV injection of tranexamic acid over 10 to 20 minutes. A second dose was given if bleeding restarted after 30 minutes and within 24 hours of the first dose.

To reduce mortality give tranexamic acid promptly

Tranexamic acid reduced mortality most effectively compared with placebo when given within 3 hours of delivery (1.2% [N = 89] vs 1.7% [N = 127]; P = .008; RR = 0.69; 95% CI 0.52-0.91; NNT = 200). After 3 hours, no significant decrease in mortality occurred. No significant difference in effect was noted between vaginal and cesarean deliveries nor between uterine atony as the primary cause of hemorrhage and other causes.

Administering tranexamic acid didn’t reduce the composite primary endpoint of hysterectomy or death from all causes. Nor did it reduce the secondary endpoints of intrauterine tamponade, embolization, manual placental extraction, arterial ligation, blood transfusions, or number of units of packed red blood cells. The tranexamic acid group showed a significant decrease in cases of laparotomy for PPH (0.8% vs 1.3%; P = .002; RR = 0.64; 95% CI, 0.49-0.85; NNT = 200).

Women who received tranexamic acid vs placebo showed no significant difference in mortality from pulmonary embolism (0.1% [N = 10] vs 0.1% [N = 11]; P = .82; RR = .9; 95% CI, 0.38-2.13), organ failure ure (0.3% [N = 25] vs 0.2% [N = 18]; P = .29; RR = 1.38; 95% CI, 0.75-2.53), sepsis (0.2% [N = 15] vs 0.1% [N = 8]; P = .15; RR = 1.87; 95% CI, 0.79-4.4), eclampsia (0.02% [N = 2] vs 0.1% [N = 8]; P = .057; RR = .25; 95% CI, 0.05-1.17), or other causes (0.2% [N = 20] vs 0.2% [N = 20]; P = .99; RR = 0.99; 95% CI, 0.54-1.85).

Tranexamic acid doesn’t increase the risk of thromboembolism

A 2018 Cochrane review sought more broadly to determine the general effectiveness and safety of antifibrinolytic drugs in treating primary PPH.² Of 15 RCTs identified, only 3 met the inclusion criteria for the review, 1 of which was the WOMAN trial (which contributed most of the data in the review). The other trials were a study conducted in France that recruited 152 women and a study of 200 women in Iran that contributed only 1 primary outcome—estimated blood loss—to the review. The former study didn’t report any maternal deaths, and the latter study didn’t look at maternal deaths. The Cochrane review concluded, based on data from the WOMAN trial, that IV tranexamic acid, if given as early as possible, reduced mortality from bleeding in women with primary PPH after both vaginal and cesarean delivery and didn’t increase the risk of thromboembolic events.²

Continue to: RECOMMENDATIONS

The newest practice guidelines on the management of postpartum hemorrhage published by the American College of Obstetricians and Gynecologists recommends considering tranexamic acid as an additional agent in managing PPH when initial standard-of-care treatments fail.³

Editor’s takeaway

The large international double-blind, randomized placebo-controlled trial provides convincing evidence that tranexamic acid should be administered readily in cases of PPH.