Marijuana Use in Pregnancy: Does the High Make You High Risk? [20E

Abstract

INTRODUCTION: To identify adverse pregnancy outcomes associated with marijuana use during pregnancy. METHODS: We conducted a secondary analysis of the prospective cohort study, “Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be” (nuMoM2b), which recruited 10,038 nulliparous women with singleton pregnancies from eight U.S. medical centers. Information regarding marijuana use was obtained using direct questionnaires during in-person interview. The composite adverse outcome included stillbirth, hypertensive disorders of pregnancy, preterm birth, and small-for-gestational-age births. Secondary outcomes assessed neonatal morbidity, specifically examining neonatal intensive care unit admission, respiratory distress syndrome, neonatal sepsis, and neonatal death. Other secondary outcomes included mode of delivery and suspected intrauterine fetal growth restriction. RESULTS: Marijuana use during pregnancy was identified in 1.3% of the nulliparous women with singleton pregnancies. Marijuana users during pregnancy were found to have an increased risk of the composite adverse outcome compared to nonusers (27.6% vs 20.4%; P=.049) with an increase small-for-gestational-age births (16.6% vs 9.5%; P=.021). After adjustment for age, BMI, race, and chronic hypertension, marijuana use was not associated with the composite adverse pregnancy outcome (adjusted odds ratio 1.27; 95% CI 0.84–1.89). CONCLUSION: Maternal marijuana use is potentially associated with an increased risk of composite adverse pregnancy outcome of stillbirth, hypertensive disorders of pregnancy, preterm birth, and small-for-gestational-age births. However, the association was not significant when controlling for possible confounders. Future studies should focus on biologic evidence of marijuana consumption as compared to self-report.