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A flurry of research papers published this year has simultaneously documented a rise in the use of cannabis during pregnancy and offered more data about its potential harms. This confluence of findings is concerning and highlights the importance of screening our patients for cannabis use and engaging with them in a way in which we can maintain their trust and their commitment to prenatal care.
A retrospective cohort study involving 661,617 women in Ontario found a significant association between self-reported cannabis use in pregnancy and an increased risk of preterm birth (relative risk, 1.41), as well as a greater likelihood of small-for-gestational-age babies (RR, 1.53), placental abruption (RR, 1.72), and transfer to neonatal intensive care (RR, 1.40).1 The study, reported in JAMA in July 2019, carefully matched users with nonusers who had the same characteristics – for example, tobacco use or not.
This new information builds upon other meta-analyses that have demonstrated a decrease in birth weight and greater admittance to the neonatal ICU associated with cannabis use in pregnancy – and it supplements what some research suggests about long-term neurologic development and a potentially increased risk of attention and behavioral problems. Other outcomes that have been noted in long-term neurologic studies of children who were exposed to cannabis in utero include impaired visual acuity, verbal reasoning and comprehension, and short-term memory.2
Increases in use were recently documented in two studies. One, an analysis of data from the National Survey on Drug Use and Health (NSDUH) published in JAMA in June 2019, showed that, between 2002-2003 and 2016-2017, the use of cannabis “in the past month” increased from 3.4% to 7.0% among pregnant women overall, and from 6% to 12% during the first trimester.3
The use of cannabis on a daily or near-daily basis, moreover, increased from 0.9% to 3% among pregnant women overall and from 2% to 5% during the first trimester. The data were collected during face-to-face interviews and were adjusted for age, race/ethnicity, and family income.
In the second study – a cross-sectional study of 367,403 pregnancies among women who filled out a questionnaire on cannabis use during standard prenatal care at Kaiser Permanente Northern California – the adjusted prevalence of use in the year before pregnancy increased from 7% in 2009 to 13% in 2017, and the adjusted prevalence during pregnancy increased from 2% to 3%.4
As in the NSDUH analysis, daily use increased most rapidly (compared with weekly or monthly) such that, by 2017, 25% of those who reported using cannabis in the year before pregnancy – and 21% of those who used cannabis during pregnancy – were daily users. It is notable that Kaiser’s population is diverse in all respects, and that the annual relative rates of increase in cannabis use before and during pregnancy (at each level of frequency) were consistent across racial/ethnic and household income groups.
It’s also worth noting that, in earlier research covering a similar time period (2009-2016), the investigators found significant increases in use via urine toxicology testing that occurs at the first prenatal visit at Kaiser. The increase found through questionnaires, therefore, reflects more than a greater willingness to self-report.
Choosing a screening tool
Universal prenatal substance use screening is recommended by the American College of Obstetricians and Gynecologists and the Centers for Disease Control and Prevention, but we don’t have any specific recommendations on what this means. Who should be screening, and what should that screening look like? Should we use a biologic screen, a standardized screening tool, or simply ask patients whether they use illicit substances?
Screening tools seem advantageous in that they are low cost, noninvasive, potentially comprehensive, and not subject to false-positive results as biologic screens can be – but which tool or tools are best? There are several validated screening tools that can be used outside of pregnancy to determine an individual’s use of illicit substances and whether or not that use is problematic, but previous studies have not used biologic markers to validate substance use screeners in pregnancy. Nor have studies compared screeners in pregnancy.
In our prenatal population in Baltimore, we have not been getting the answers we want using various nonvalidated screening tools. Approximately 30% of patients are positive for cannabis by urine screen, but only half tell us about their use.
Through research in our two prenatal care practices (one serving mostly privately insured and the other serving primarily Medicaid-eligible patients), we assessed both the accuracy and the acceptability of three substance use screening tools that are brief and that have been validated (for the general population) by the World Health Organization for screening of multiple substances: the 4P’s Plus (Parents, Partner, Past, and Pregnancy), the National Institute on Drug Abuse Quick Screen–ASSIST (Modified Alcohol, Smoking and Substance Involvement Screening Test), and the SURP-P (Substance Use Risk Profile–Pregnancy) scale.
In one study, published in May 2019 in Obstetrics & Gynecology, we recruited 500 pregnant women and administered these three tests to each of them.5 We then compared results with those of urine and hair drug testing, and checked the test-retest reliability of each test by readministering them (albeit by telephone) a week later. Although hair testing is not an indicator of current substance use, we used it to validate the screening tools on less-recent use.
The tests with the highest sensitivity and negative predictive values – the qualities we most want for screening – were the SURP-P and the 4P’s Plus (sensitivity of 92.4% and 90.2%, respectively). Overall they were highly sensitive screening tools across all trimesters, races, and age groups, making them more ideal screening tests than the NIDA Quick Screen–ASSIST.
Of the two tests, the 4P’s Plus screening tool was the one preferred by staff from both practices. In a companion qualitative study, we conducted focus-group discussions with 40 practice staff who were responsible for administering or overseeing patient screening.6 The staff, who were unaware of the sensitivity findings, were asked what they thought about the acceptability to patients of each of the three tools and their usability in practice.
Most of the participating staff preferred the 4P’s Plus screening tool for several reasons: It is easy to understand, is brief and to the point, and it has nonjudgmental language and tone. The screener first asks the patient about her parents’ and her partner’s use of alcohol and drugs, and then asks the patient about her own use of alcohol and tobacco. Affirmative responses to these questions lead to additional questions.
The premise is that one’s genetics, history, and current exposures – as well as one’s own use of tobacco and alcohol – are significantly associated with the use of illicit substances. If the patient reports no parental history or partner usage, and has never drank or smoked before, it’s extremely unlikely that she is using other drugs. The progression of questions does indeed seem less judgmental than immediately asking: “Do you use drugs?”
For us, the insight from this staff perception study combined with the findings on accuracy mean that the 4P’s Plus may be the most useful and acceptable screening tool for routine use in prenatal care.
Talking with our patients
The increase in the use of cannabis before and after pregnancy parallels the movement toward state legalization and decriminalization. Historically, clinicians often have relied on illegality as their main focus of counseling when giving recommendations for cessation and abstinence in pregnancy.2 This approach not only leads to punitive counseling, which can fracture the doctor-patient relationship, but increasingly it is no longer valid. In our changing legal climate, we need to provide medically based counseling and be very clear with our patients that legalization does not equate to safety.
It is important that we neither minimize nor overstate the risks. The evidence base for adverse birth outcomes of cannabis use in pregnancy is quite robust, but the associations can be subtle and are moderated by other behaviors and environmental factors that continue to challenge researchers.
As with alcohol, there likely are dose-or trimester-dependent differences in perinatal outcomes, and it’s quite possible that different cannabis products and routes of consumption have different effects. At this point, however, we don’t know the full story, nor do we know the extent to which the literature is biased toward positive correlations – the reporting of adverse effects – compared with negative findings. It is our job as medical care providers to be comfortable in that gray area and to still counsel patients on what we do know, providing the best-possible medical advice based on the information available to us.
In talking with patients, I explain that cannabis may cause a spectrum of problems and that there certainly are risks. I also tell them that we’re uncertain about the conditions and magnitude of that risk and that some babies who are exposed to cannabis in utero may have no perceivable consequences. Such honesty is important for maintaining trust, especially as some patients may see friends and relatives who also are cannabis users have normal pregnancy outcomes.
Much of my concern about cannabis in pregnancy centers on its effect on the developing brain and on long-term neurologic development. I share this with patients – I tell them that cannabis crosses the placenta and may well affect their baby’s brain as it is developing. I explain that I do not know whether this effect would be big or small, but that it’s not a chance I’m willing to take for their baby.
It is also important to educate patients that cannabis products are untested and unregulated and that they may be contaminated with heavy metals, pesticides, and other toxins that may be harmful to themselves and their babies. Patients also should know that the potency of cannabis has been dramatically increasing; research shows that the tetrahydrocannabinol – the psychoactive component – concentration has tripled over the past 2 decades.7
Research tells us that women who use illicit drugs and alcohol categorically engage in some form of harm reduction once they learn they are pregnant, and the same is true for cannabis. This is seen in dramatically different rates of first- and third-trimester use in the new analysis of NSDUH data; third-trimester use is approximately halved.
Some women will not be able to discontinue use, however, or they may try to quit and fail in their attempts. As we should with substance use more broadly, we must meet patients where they are, view cannabis use as a chronic medical problem, offer our assistance in helping them reduce harms of their use, and understand that quitting is a process.
Screening for mental health disorders and trauma is, of course, especially important in patients who use cannabis and other substances recreationally. In cases of medical marijuana usage, I recommend, as ACOG and other have done, that we discuss the risks and benefits of continuing cannabis versus shifting to alternative medications if options exist.
All patients should be welcomed, congratulated on their pregnancy and on coming for prenatal care, and engaged in the overall process of optimizing their health and the health of their baby. Like any other health issue during pregnancy, cannabis use needs to be screened for and treated in an evidence-based manner, but it does not define the trajectory or success of a woman’s pregnancy or her ability to be a successful parent.
Dr. Mark is associate professor of obstetrics, gynecology, and reproductive sciences at the University of Maryland School of Medicine.
References
1. JAMA. 2019 Jul 9;322(2):145-52.
2. Preventive Medicine 2017 May 18;104:46-9.
3. JAMA. 2019 Jul 9;322(2):167-9.
4. JAMA Netw Open. 2019 Jul 3;2(7):e196471.
5. Obstet Gynecol. 2019 May;133(5):952-61.
6. J. Addict Med. 2019 May 10. doi: 10.1097/ADM.0000000000000543.
7. Biol Psychiatry. 2016 Apr 1;79(7):613-9.
A flurry of research papers published this year has simultaneously documented a rise in the use of cannabis during pregnancy and offered more data about its potential harms. This confluence of findings is concerning and highlights the importance of screening our patients for cannabis use and engaging with them in a way in which we can maintain their trust and their commitment to prenatal care.
A retrospective cohort study involving 661,617 women in Ontario found a significant association between self-reported cannabis use in pregnancy and an increased risk of preterm birth (relative risk, 1.41), as well as a greater likelihood of small-for-gestational-age babies (RR, 1.53), placental abruption (RR, 1.72), and transfer to neonatal intensive care (RR, 1.40).1 The study, reported in JAMA in July 2019, carefully matched users with nonusers who had the same characteristics – for example, tobacco use or not.
This new information builds upon other meta-analyses that have demonstrated a decrease in birth weight and greater admittance to the neonatal ICU associated with cannabis use in pregnancy – and it supplements what some research suggests about long-term neurologic development and a potentially increased risk of attention and behavioral problems. Other outcomes that have been noted in long-term neurologic studies of children who were exposed to cannabis in utero include impaired visual acuity, verbal reasoning and comprehension, and short-term memory.2
Increases in use were recently documented in two studies. One, an analysis of data from the National Survey on Drug Use and Health (NSDUH) published in JAMA in June 2019, showed that, between 2002-2003 and 2016-2017, the use of cannabis “in the past month” increased from 3.4% to 7.0% among pregnant women overall, and from 6% to 12% during the first trimester.3
The use of cannabis on a daily or near-daily basis, moreover, increased from 0.9% to 3% among pregnant women overall and from 2% to 5% during the first trimester. The data were collected during face-to-face interviews and were adjusted for age, race/ethnicity, and family income.
In the second study – a cross-sectional study of 367,403 pregnancies among women who filled out a questionnaire on cannabis use during standard prenatal care at Kaiser Permanente Northern California – the adjusted prevalence of use in the year before pregnancy increased from 7% in 2009 to 13% in 2017, and the adjusted prevalence during pregnancy increased from 2% to 3%.4
As in the NSDUH analysis, daily use increased most rapidly (compared with weekly or monthly) such that, by 2017, 25% of those who reported using cannabis in the year before pregnancy – and 21% of those who used cannabis during pregnancy – were daily users. It is notable that Kaiser’s population is diverse in all respects, and that the annual relative rates of increase in cannabis use before and during pregnancy (at each level of frequency) were consistent across racial/ethnic and household income groups.
It’s also worth noting that, in earlier research covering a similar time period (2009-2016), the investigators found significant increases in use via urine toxicology testing that occurs at the first prenatal visit at Kaiser. The increase found through questionnaires, therefore, reflects more than a greater willingness to self-report.
Choosing a screening tool
Universal prenatal substance use screening is recommended by the American College of Obstetricians and Gynecologists and the Centers for Disease Control and Prevention, but we don’t have any specific recommendations on what this means. Who should be screening, and what should that screening look like? Should we use a biologic screen, a standardized screening tool, or simply ask patients whether they use illicit substances?
Screening tools seem advantageous in that they are low cost, noninvasive, potentially comprehensive, and not subject to false-positive results as biologic screens can be – but which tool or tools are best? There are several validated screening tools that can be used outside of pregnancy to determine an individual’s use of illicit substances and whether or not that use is problematic, but previous studies have not used biologic markers to validate substance use screeners in pregnancy. Nor have studies compared screeners in pregnancy.
In our prenatal population in Baltimore, we have not been getting the answers we want using various nonvalidated screening tools. Approximately 30% of patients are positive for cannabis by urine screen, but only half tell us about their use.
Through research in our two prenatal care practices (one serving mostly privately insured and the other serving primarily Medicaid-eligible patients), we assessed both the accuracy and the acceptability of three substance use screening tools that are brief and that have been validated (for the general population) by the World Health Organization for screening of multiple substances: the 4P’s Plus (Parents, Partner, Past, and Pregnancy), the National Institute on Drug Abuse Quick Screen–ASSIST (Modified Alcohol, Smoking and Substance Involvement Screening Test), and the SURP-P (Substance Use Risk Profile–Pregnancy) scale.
In one study, published in May 2019 in Obstetrics & Gynecology, we recruited 500 pregnant women and administered these three tests to each of them.5 We then compared results with those of urine and hair drug testing, and checked the test-retest reliability of each test by readministering them (albeit by telephone) a week later. Although hair testing is not an indicator of current substance use, we used it to validate the screening tools on less-recent use.
The tests with the highest sensitivity and negative predictive values – the qualities we most want for screening – were the SURP-P and the 4P’s Plus (sensitivity of 92.4% and 90.2%, respectively). Overall they were highly sensitive screening tools across all trimesters, races, and age groups, making them more ideal screening tests than the NIDA Quick Screen–ASSIST.
Of the two tests, the 4P’s Plus screening tool was the one preferred by staff from both practices. In a companion qualitative study, we conducted focus-group discussions with 40 practice staff who were responsible for administering or overseeing patient screening.6 The staff, who were unaware of the sensitivity findings, were asked what they thought about the acceptability to patients of each of the three tools and their usability in practice.
Most of the participating staff preferred the 4P’s Plus screening tool for several reasons: It is easy to understand, is brief and to the point, and it has nonjudgmental language and tone. The screener first asks the patient about her parents’ and her partner’s use of alcohol and drugs, and then asks the patient about her own use of alcohol and tobacco. Affirmative responses to these questions lead to additional questions.
The premise is that one’s genetics, history, and current exposures – as well as one’s own use of tobacco and alcohol – are significantly associated with the use of illicit substances. If the patient reports no parental history or partner usage, and has never drank or smoked before, it’s extremely unlikely that she is using other drugs. The progression of questions does indeed seem less judgmental than immediately asking: “Do you use drugs?”
For us, the insight from this staff perception study combined with the findings on accuracy mean that the 4P’s Plus may be the most useful and acceptable screening tool for routine use in prenatal care.
Talking with our patients
The increase in the use of cannabis before and after pregnancy parallels the movement toward state legalization and decriminalization. Historically, clinicians often have relied on illegality as their main focus of counseling when giving recommendations for cessation and abstinence in pregnancy.2 This approach not only leads to punitive counseling, which can fracture the doctor-patient relationship, but increasingly it is no longer valid. In our changing legal climate, we need to provide medically based counseling and be very clear with our patients that legalization does not equate to safety.
It is important that we neither minimize nor overstate the risks. The evidence base for adverse birth outcomes of cannabis use in pregnancy is quite robust, but the associations can be subtle and are moderated by other behaviors and environmental factors that continue to challenge researchers.
As with alcohol, there likely are dose-or trimester-dependent differences in perinatal outcomes, and it’s quite possible that different cannabis products and routes of consumption have different effects. At this point, however, we don’t know the full story, nor do we know the extent to which the literature is biased toward positive correlations – the reporting of adverse effects – compared with negative findings. It is our job as medical care providers to be comfortable in that gray area and to still counsel patients on what we do know, providing the best-possible medical advice based on the information available to us.
In talking with patients, I explain that cannabis may cause a spectrum of problems and that there certainly are risks. I also tell them that we’re uncertain about the conditions and magnitude of that risk and that some babies who are exposed to cannabis in utero may have no perceivable consequences. Such honesty is important for maintaining trust, especially as some patients may see friends and relatives who also are cannabis users have normal pregnancy outcomes.
Much of my concern about cannabis in pregnancy centers on its effect on the developing brain and on long-term neurologic development. I share this with patients – I tell them that cannabis crosses the placenta and may well affect their baby’s brain as it is developing. I explain that I do not know whether this effect would be big or small, but that it’s not a chance I’m willing to take for their baby.
It is also important to educate patients that cannabis products are untested and unregulated and that they may be contaminated with heavy metals, pesticides, and other toxins that may be harmful to themselves and their babies. Patients also should know that the potency of cannabis has been dramatically increasing; research shows that the tetrahydrocannabinol – the psychoactive component – concentration has tripled over the past 2 decades.7
Research tells us that women who use illicit drugs and alcohol categorically engage in some form of harm reduction once they learn they are pregnant, and the same is true for cannabis. This is seen in dramatically different rates of first- and third-trimester use in the new analysis of NSDUH data; third-trimester use is approximately halved.
Some women will not be able to discontinue use, however, or they may try to quit and fail in their attempts. As we should with substance use more broadly, we must meet patients where they are, view cannabis use as a chronic medical problem, offer our assistance in helping them reduce harms of their use, and understand that quitting is a process.
Screening for mental health disorders and trauma is, of course, especially important in patients who use cannabis and other substances recreationally. In cases of medical marijuana usage, I recommend, as ACOG and other have done, that we discuss the risks and benefits of continuing cannabis versus shifting to alternative medications if options exist.
All patients should be welcomed, congratulated on their pregnancy and on coming for prenatal care, and engaged in the overall process of optimizing their health and the health of their baby. Like any other health issue during pregnancy, cannabis use needs to be screened for and treated in an evidence-based manner, but it does not define the trajectory or success of a woman’s pregnancy or her ability to be a successful parent.
Dr. Mark is associate professor of obstetrics, gynecology, and reproductive sciences at the University of Maryland School of Medicine.
References
1. JAMA. 2019 Jul 9;322(2):145-52.
2. Preventive Medicine 2017 May 18;104:46-9.
3. JAMA. 2019 Jul 9;322(2):167-9.
4. JAMA Netw Open. 2019 Jul 3;2(7):e196471.
5. Obstet Gynecol. 2019 May;133(5):952-61.
6. J. Addict Med. 2019 May 10. doi: 10.1097/ADM.0000000000000543.
7. Biol Psychiatry. 2016 Apr 1;79(7):613-9.
A flurry of research papers published this year has simultaneously documented a rise in the use of cannabis during pregnancy and offered more data about its potential harms. This confluence of findings is concerning and highlights the importance of screening our patients for cannabis use and engaging with them in a way in which we can maintain their trust and their commitment to prenatal care.
A retrospective cohort study involving 661,617 women in Ontario found a significant association between self-reported cannabis use in pregnancy and an increased risk of preterm birth (relative risk, 1.41), as well as a greater likelihood of small-for-gestational-age babies (RR, 1.53), placental abruption (RR, 1.72), and transfer to neonatal intensive care (RR, 1.40).1 The study, reported in JAMA in July 2019, carefully matched users with nonusers who had the same characteristics – for example, tobacco use or not.
This new information builds upon other meta-analyses that have demonstrated a decrease in birth weight and greater admittance to the neonatal ICU associated with cannabis use in pregnancy – and it supplements what some research suggests about long-term neurologic development and a potentially increased risk of attention and behavioral problems. Other outcomes that have been noted in long-term neurologic studies of children who were exposed to cannabis in utero include impaired visual acuity, verbal reasoning and comprehension, and short-term memory.2
Increases in use were recently documented in two studies. One, an analysis of data from the National Survey on Drug Use and Health (NSDUH) published in JAMA in June 2019, showed that, between 2002-2003 and 2016-2017, the use of cannabis “in the past month” increased from 3.4% to 7.0% among pregnant women overall, and from 6% to 12% during the first trimester.3
The use of cannabis on a daily or near-daily basis, moreover, increased from 0.9% to 3% among pregnant women overall and from 2% to 5% during the first trimester. The data were collected during face-to-face interviews and were adjusted for age, race/ethnicity, and family income.
In the second study – a cross-sectional study of 367,403 pregnancies among women who filled out a questionnaire on cannabis use during standard prenatal care at Kaiser Permanente Northern California – the adjusted prevalence of use in the year before pregnancy increased from 7% in 2009 to 13% in 2017, and the adjusted prevalence during pregnancy increased from 2% to 3%.4
As in the NSDUH analysis, daily use increased most rapidly (compared with weekly or monthly) such that, by 2017, 25% of those who reported using cannabis in the year before pregnancy – and 21% of those who used cannabis during pregnancy – were daily users. It is notable that Kaiser’s population is diverse in all respects, and that the annual relative rates of increase in cannabis use before and during pregnancy (at each level of frequency) were consistent across racial/ethnic and household income groups.
It’s also worth noting that, in earlier research covering a similar time period (2009-2016), the investigators found significant increases in use via urine toxicology testing that occurs at the first prenatal visit at Kaiser. The increase found through questionnaires, therefore, reflects more than a greater willingness to self-report.
Choosing a screening tool
Universal prenatal substance use screening is recommended by the American College of Obstetricians and Gynecologists and the Centers for Disease Control and Prevention, but we don’t have any specific recommendations on what this means. Who should be screening, and what should that screening look like? Should we use a biologic screen, a standardized screening tool, or simply ask patients whether they use illicit substances?
Screening tools seem advantageous in that they are low cost, noninvasive, potentially comprehensive, and not subject to false-positive results as biologic screens can be – but which tool or tools are best? There are several validated screening tools that can be used outside of pregnancy to determine an individual’s use of illicit substances and whether or not that use is problematic, but previous studies have not used biologic markers to validate substance use screeners in pregnancy. Nor have studies compared screeners in pregnancy.
In our prenatal population in Baltimore, we have not been getting the answers we want using various nonvalidated screening tools. Approximately 30% of patients are positive for cannabis by urine screen, but only half tell us about their use.
Through research in our two prenatal care practices (one serving mostly privately insured and the other serving primarily Medicaid-eligible patients), we assessed both the accuracy and the acceptability of three substance use screening tools that are brief and that have been validated (for the general population) by the World Health Organization for screening of multiple substances: the 4P’s Plus (Parents, Partner, Past, and Pregnancy), the National Institute on Drug Abuse Quick Screen–ASSIST (Modified Alcohol, Smoking and Substance Involvement Screening Test), and the SURP-P (Substance Use Risk Profile–Pregnancy) scale.
In one study, published in May 2019 in Obstetrics & Gynecology, we recruited 500 pregnant women and administered these three tests to each of them.5 We then compared results with those of urine and hair drug testing, and checked the test-retest reliability of each test by readministering them (albeit by telephone) a week later. Although hair testing is not an indicator of current substance use, we used it to validate the screening tools on less-recent use.
The tests with the highest sensitivity and negative predictive values – the qualities we most want for screening – were the SURP-P and the 4P’s Plus (sensitivity of 92.4% and 90.2%, respectively). Overall they were highly sensitive screening tools across all trimesters, races, and age groups, making them more ideal screening tests than the NIDA Quick Screen–ASSIST.
Of the two tests, the 4P’s Plus screening tool was the one preferred by staff from both practices. In a companion qualitative study, we conducted focus-group discussions with 40 practice staff who were responsible for administering or overseeing patient screening.6 The staff, who were unaware of the sensitivity findings, were asked what they thought about the acceptability to patients of each of the three tools and their usability in practice.
Most of the participating staff preferred the 4P’s Plus screening tool for several reasons: It is easy to understand, is brief and to the point, and it has nonjudgmental language and tone. The screener first asks the patient about her parents’ and her partner’s use of alcohol and drugs, and then asks the patient about her own use of alcohol and tobacco. Affirmative responses to these questions lead to additional questions.
The premise is that one’s genetics, history, and current exposures – as well as one’s own use of tobacco and alcohol – are significantly associated with the use of illicit substances. If the patient reports no parental history or partner usage, and has never drank or smoked before, it’s extremely unlikely that she is using other drugs. The progression of questions does indeed seem less judgmental than immediately asking: “Do you use drugs?”
For us, the insight from this staff perception study combined with the findings on accuracy mean that the 4P’s Plus may be the most useful and acceptable screening tool for routine use in prenatal care.
Talking with our patients
The increase in the use of cannabis before and after pregnancy parallels the movement toward state legalization and decriminalization. Historically, clinicians often have relied on illegality as their main focus of counseling when giving recommendations for cessation and abstinence in pregnancy.2 This approach not only leads to punitive counseling, which can fracture the doctor-patient relationship, but increasingly it is no longer valid. In our changing legal climate, we need to provide medically based counseling and be very clear with our patients that legalization does not equate to safety.
It is important that we neither minimize nor overstate the risks. The evidence base for adverse birth outcomes of cannabis use in pregnancy is quite robust, but the associations can be subtle and are moderated by other behaviors and environmental factors that continue to challenge researchers.
As with alcohol, there likely are dose-or trimester-dependent differences in perinatal outcomes, and it’s quite possible that different cannabis products and routes of consumption have different effects. At this point, however, we don’t know the full story, nor do we know the extent to which the literature is biased toward positive correlations – the reporting of adverse effects – compared with negative findings. It is our job as medical care providers to be comfortable in that gray area and to still counsel patients on what we do know, providing the best-possible medical advice based on the information available to us.
In talking with patients, I explain that cannabis may cause a spectrum of problems and that there certainly are risks. I also tell them that we’re uncertain about the conditions and magnitude of that risk and that some babies who are exposed to cannabis in utero may have no perceivable consequences. Such honesty is important for maintaining trust, especially as some patients may see friends and relatives who also are cannabis users have normal pregnancy outcomes.
Much of my concern about cannabis in pregnancy centers on its effect on the developing brain and on long-term neurologic development. I share this with patients – I tell them that cannabis crosses the placenta and may well affect their baby’s brain as it is developing. I explain that I do not know whether this effect would be big or small, but that it’s not a chance I’m willing to take for their baby.
It is also important to educate patients that cannabis products are untested and unregulated and that they may be contaminated with heavy metals, pesticides, and other toxins that may be harmful to themselves and their babies. Patients also should know that the potency of cannabis has been dramatically increasing; research shows that the tetrahydrocannabinol – the psychoactive component – concentration has tripled over the past 2 decades.7
Research tells us that women who use illicit drugs and alcohol categorically engage in some form of harm reduction once they learn they are pregnant, and the same is true for cannabis. This is seen in dramatically different rates of first- and third-trimester use in the new analysis of NSDUH data; third-trimester use is approximately halved.
Some women will not be able to discontinue use, however, or they may try to quit and fail in their attempts. As we should with substance use more broadly, we must meet patients where they are, view cannabis use as a chronic medical problem, offer our assistance in helping them reduce harms of their use, and understand that quitting is a process.
Screening for mental health disorders and trauma is, of course, especially important in patients who use cannabis and other substances recreationally. In cases of medical marijuana usage, I recommend, as ACOG and other have done, that we discuss the risks and benefits of continuing cannabis versus shifting to alternative medications if options exist.
All patients should be welcomed, congratulated on their pregnancy and on coming for prenatal care, and engaged in the overall process of optimizing their health and the health of their baby. Like any other health issue during pregnancy, cannabis use needs to be screened for and treated in an evidence-based manner, but it does not define the trajectory or success of a woman’s pregnancy or her ability to be a successful parent.
Dr. Mark is associate professor of obstetrics, gynecology, and reproductive sciences at the University of Maryland School of Medicine.
References
1. JAMA. 2019 Jul 9;322(2):145-52.
2. Preventive Medicine 2017 May 18;104:46-9.
3. JAMA. 2019 Jul 9;322(2):167-9.
4. JAMA Netw Open. 2019 Jul 3;2(7):e196471.
5. Obstet Gynecol. 2019 May;133(5):952-61.
6. J. Addict Med. 2019 May 10. doi: 10.1097/ADM.0000000000000543.
7. Biol Psychiatry. 2016 Apr 1;79(7):613-9.