Frequent Cannabis Use During Pregnancy Was Linked to 3.4x Higher Odds of Hypertension

Cannabis use as a binary variable (yes/no) was not associated with higher odds of hypertension during pregnancy (OR 0.86). However, among those who used cannabis, frequent use (2-6 times per week to daily) was associated with 3.44 times higher odds of hypertensive disorders compared to minimal use (once per month or less, OR 3.44, 95% CI 1.40-8.43).

Retrospective cohort study using 2017-2018 Pregnancy Risk Assessment Monitoring System (PRAMS) data (n=10,911, weighted n=587,486). Cannabis use frequency was categorized as no use, minimal (1x/month or less), moderate (2x/month to 1 day/week), and frequent (2-6x/week to daily). Multivariable logistic regression examined dose-response.

This study may explain why prior research on cannabis and pregnancy hypertension has been mixed: looking at any use versus no use masks a dose-response relationship. The finding that frequency matters has practical implications for prenatal screening and counseling.

Hypertensive disorders of pregnancy (including preeclampsia) are a leading cause of maternal and fetal morbidity. As cannabis use during pregnancy increases, understanding dose-response relationships is critical for clinical guidance beyond simple "use vs. no use" recommendations.

Self-reported cannabis use may underestimate true frequency. PRAMS data are cross-sectional and cannot establish causation. Relatively small numbers in the frequent use category. Cannot account for cannabis potency, method of consumption, or specific cannabinoid profiles. Potential for residual confounding.