Prenatal cannabis use may be associated with increased risks of gestational hypertension, preeclampsia, and placental abruption; conversely, it seemed to decrease the risk of gestational diabetes, according to a recent study.
The study, published in JAMA Internal Medicine, aimed to evaluate whether prenatal cannabis use showed any associations with maternal health outcomes. The retrospective cohort study included 316,722 pregnancies from 250,221 distinct patients in Northern California from 2011 to 2019. The demographic breakdown was 26.5% Asian/Pacific Islander, 6.3% Black, 26.3% Hispanic, and 37.4% White, with an average patient age of 30.6 years.
The study defined prenatal cannabis use through self-reported data and toxicology tests performed at approximately 8 to 10 weeks gestation. The study found that 20,053 patients (6.3%) tested positive for prenatal cannabis use. Among these, 2.9% were identified through self-reporting, 5.3% through positive toxicology testing, and 1.8% through both methods. Regarding frequency, 0.6% used cannabis daily, 0.7% weekly, 1.5% monthly or less, and 3.4% had an unknown frequency of use.
The analysis found associations between prenatal cannabis use and an increased risk of gestational hypertension (adjusted risk ratio [aRR], 1.17; 95% confidence interval [CI], 1.13-1.21), preeclampsia (aRR, 1.08; 95% CI, 1.01-1.15), weight gain outside of recommended guidelines (aRR, 1.05-1.09; 95% CI, 1.01-1.10), and placental abruption (aRR, 1.19; 95% CI, 1.05-1.36). Prenatal cannabis use was also associated with a decreased risk of gestational diabetes (aRR, 0.89; 95% CI, 0.85-0.94). There were no associations seen with prenatal cannabis use and eclampsia, placenta previa, placenta accreta, or severe maternal morbidity.
Adjustments were made for sociodemographic factors and maternal use of other substances. These findings illustrated the complexity of prenatal cannabis use and its potential impact on maternal health.
The study sample consisted solely of insured patients in Northern California. There may be an underestimation of cannabis use since the data relied partly on self-reports. Additionally, the study did not account for potential unmeasured confounders or variations in cannabis potency and methods of use.
The study authors concluded, "The findings suggest a complex association between prenatal cannabis use and maternal health and highlight the need for continued research to understand the mechanisms through which prenatal cannabis use is associated with the health of pregnant individuals. Prenatal cannabis use is a risk factor for adverse neonatal outcomes. As we continue to learn about the potential harms and benefits of prenatal cannabis use, clinicians must provide coordinated, nonstigmatizing care and education to support pregnant individuals in making informed decisions about cannabis use."
The study was funded by the National Institute on Drug Abuse, with Kelly C. Young-Wolff, PhD, MPH, and colleagues reporting grants from the NIH. No other disclosures were reported.
