Prenatal Cannabis Use Linked to Adverse Maternal Health Outcomes: JAMA Study

While prenatal cannabis use has been widely investigated for its effects on fetal and neonatal outcomes, much less is known about its implications for maternal health. This was a population-based retrospective cohort study to determine whether there is an association between prenatal cannabis use and various maternal health outcomes during pregnancy. The study examined data from pregnancies in Northern California occurring from January 2011 to December 2019.

This was a cohort study of pregnancies at a minimum gestational age of 20 weeks, screened for prenatal cannabis use using an electronic health record. Prenatal cannabis use was ascertained by self-report or positive toxicology tests at the initiation of prenatal care, approximately 8-10 weeks of gestation. Measurements included gestational hypertension, preeclampsia, eclampsia, gestational diabetes, and a set of complications related to placental health. The risk ratios were estimated by the investigators using a modified Poisson regression model, accounting for a number of potential confounders.

Key Findings

• Prenatal cannabis use was associated with a 17% increased risk of gestational hypertension (aRR, 1.17; 95% CI, 1.13-1.21).

• The risk of preeclampsia was 8% higher among those who used cannabis during pregnancy (aRR, 1.08; 95% CI, 1.01-1.15).

• Cannabis use was linked to both insufficient and excessive weight gain during pregnancy.

• A 5% increased risk of weight gain less than guidelines, (aRR 1.05, 95% CI 1.01 to 1.08), and 9% increased risk of weight gain greater than guidelines, (aRR 1.09, 95% CI 1.08 to 1.10).

• Users were at 19% increased risk of placental abruption, with an adjusted (RR of 1.19 and a 95% CI of 1.05–1.36).

• It reported similar associations, whether prenatal cannabis use was defined by self-report or by toxicology testing, with variations dependent on the frequency of use.

This study found significant associations between prenatal cannabis use and gestational hypertension, preeclampsia, anomalous weight gain, and placental abruption. Accordingly, these data suggest that prenatal exposure to cannabis is not only dangerous for fetal and neonatal health but may also be potentially dangerous for the life course of a mother.

Prenatal cannabis use is linked to several adverse maternal health outcomes, emphasizing the need for further research to understand the influence of cannabis characteristics—such as dose, mode, and timing—on these associations. Pregnant individuals and healthcare providers should be aware of these potential risks when considering cannabis use during pregnancy.

Reference:

Young-Wolff, K. C., Adams, S. R., Alexeeff, S. E., Zhu, Y., Chojolan, E., Slama, N. E., Does, M. B., Silver, L. D., Ansley, D., Castellanos, C. L., & Avalos, L. A. (2024). Prenatal cannabis use and maternal pregnancy outcomes. JAMA Internal Medicine. https://doi.org/10.1001/jamainternmed.2024.3270