INTRODUCTION
The American College of Obstetricians and Gynecology recommends discontinuing cannabis use during pregnancy because of concerns that cannabis exposure could cause adverse maternal and fetal outcomes [1]. Despite potential risks, the US prevalence of cannabis use during pregnancy increased from 2002 to 2014 [2]. During the same period, the prevalence of alcohol use during pregnancy decreased [3]. Continuing to monitor these trends, identifying patterns of cannabis during pregnancy, and examining co-use of cannabis with alcohol—a well-known teratogen, will help inform public health and clinical interventions.
We used data from the 2002–2020 National Survey on Drug Use and Health (NSDUH) to estimate trends in the prevalence of self-reported cannabis use among pregnant and non-pregnant reproductive aged individuals. We stratified prevalence estimates among pregnant individuals by trimester and by co-alcohol use, and using the most recently available data from 2020, we describe frequency of use, availability of cannabis, and source of cannabis last consumed.
METHODS
The NSDUH includes repeated cross-sectional surveys of the US civilian, noninstitutionalized population. Participants were recruited through random sampling of households. We analyzed data from pregnant and non-pregnant self-identifying females ages 12 to 44. Pregnancy status and substance use were reported via online surveys. Participants that reported ever using cannabis were asked whether their last use was within the past 30 days, how many days in the past month they used, how difficult it is for them to access cannabis, and how they obtained the last cannabis used. Similar questions were asked about alcohol. We combined alcohol and cannabis use data to define three groups: past month alcohol use with no cannabis, cannabis use with no alcohol, and use of both substances. We estimated weighted prevalence estimates and 95% confidence intervals using the Substance Abuse & Mental Health Data Archive data analysis tool [4].
RESULTS
Across all years, the prevalence of cannabis use was higher among non-pregnant compared to pregnant individuals. Among pregnant individuals, the prevalence increased from 2002 to 2020 among those in their first trimester (2002: 6.3% to 2020: 16.0%), second trimester (2002: 1.9% to 2020: 4.2%), and third trimester (2002: 2.0% to 2020: 4.7%) (Figure 1A). Within the first trimester, the prevalence among those in their first month of pregnancy was much larger than the prevalence reported among those in their second and third months of pregnancy.
Figure 1. US trends in cannabis and alcohol use among pregnant individuals from the National Survey on Drug Use and Health, 2002-2020.
(A) prevalence of self-reported past 30-day cannabis use by pregnancy status, and (B) prevalence of cannabis and alcohol co-use patterns among pregnant individuals. All plotted estimates are smoothed over three year intervals such that, for example, the prevalence estimate for 2019 is interpreted as the average prevalence between 2018-2020.
We observed a small decrease in the prevalence of alcohol use with no cannabis (2002: 8.1% to 2020: 6.4%). We observed a large increase in the prevalence of cannabis use with no alcohol (2002: 1.5% to 2020: 5.4%) and a smaller increase in the prevalence of use of both substances (2002: 1.6% to 2020: 3.0%) (Figure 1B).
Among pregnant individuals reporting past month cannabis use in 2020, 26.4% reported using almost daily (20 to 30 days per month), 34.1% reported using 6 to 19 days, 15.8% reported using 3 to 5 days, and 24.7% reported using 1 to 2 days in the past month. Over 90% of these individuals reported that cannabis was fairly or very easy to obtain and 37.5% reported that the last cannabis they used was bought from a dispensary or store.
DISCUSSION
The prevalence of cannabis use among pregnant and non-pregnant individuals increased between 2002 and 2020. Among pregnant individuals, the greatest prevalence of use was reported by people in the early months of pregnancy which could be driven by use prior to pregnancy recognition. Alcohol use during pregnancy declined during the study period. The fastest growing group were individuals that used cannabis without alcohol, suggesting that those using cannabis and those using alcohol are distinct populations. This could also suggest that some individuals may be using cannabis as a substitute for alcohol during pregnancy. Lastly, the large proportion of cannabis use purchased from stores or dispensaries suggests that interventions providing education about cannabis use in pregnancy at time of sale may be beneficial.
This study has several limitations. Cannabis and alcohol use were self-reported and estimates may underestimate true prevalence of use. A small number of pregnant individuals at each time point led to imprecise estimates. Several variables that could be used to better characterize patterns of use in pregnancy were unmeasured. These include timing of pregnancy recognition, whether the pregnancy was planned, and reasons for use. Ongoing surveillance of cannabis use during pregnancy is needed, and survey data should be expanded to capture reasons for use and route of cannabis exposure. Further research is needed to identify the drivers of cannabis use during pregnancy and identify subgroups that may benefit from additional resources.
Contributor Information
Shana Hayes, University of California, San Diego Center for Better Beginnings.
Erin Delker, University of California, San Diego and San Diego State University; University of California, San Diego Center for Better Beginnings.
Gretchen Bandoli, University of California, Los Angeles; University of California, San Diego Center for Better Beginnings.
REFERENCES
- 1.Committee Opinion No. 722: Marijuana Use During Pregnancy and Lactation. Obstet Gynecol. 2017;130(4):e205–e209. doi: 10.1097/AOG.0000000000002354 [DOI] [PubMed] [Google Scholar]
- 2.Brown QL, Sarvet AL, Shmulewitz D, Martins SS, Wall MM, Hasin DS. Trends in Marijuana Use Among Pregnant and Nonpregnant Reproductive-Aged Women, 2002-2014. JAMA. 2017;317(2):207. doi: 10.1001/jama.2016.17383 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Hasin DS, Shmulewitz D, Keyes K. Alcohol use and binge drinking among US men, pregnant and non-pregnant women ages 18–44: 2002–2017. Drug Alcohol Depend. 2019;205:107590. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. (2018). National Survey on Drug Use and Health 2002-2020 (NSDUH-2002-2020-DS0001). Retrieved from. [Google Scholar]