The Impact of Frequency of Cannabis Use on Hypertensive Disorders During Pregnancy.

Objectives: Cannabis is 1 of the most commonly used substances during pregnancy, and there is mixed evidence of its impact on maternal outcomes, such as hypertensive disorders. Prior research on cannabis use during pregnancy has not accounted for use frequency, which might explain mixed results across studies. The objective of this study was to examine how frequencies of use during pregnancy are associated with hypertensive disorders.

Methods: This was a retrospective cohort study of the 2017-2018 Pregnancy Risk Assessment Monitoring System survey (n = 10,911/weighted n = 587,486). Frequency of cannabis use was categorized for analysis as follows: no use, minimal use (1 time per month or less), moderate use (2 times per month to 1 day per week), and frequent use (2-6 times per week to daily). Multivariable logistic regression models were used to examine how the frequency of cannabis use influenced the odds of experiencing hypertensive disorders during pregnancy.

Results: Cannabis use, measured as a binary exposure variable (yes/no), was not associated with higher odds of hypertension during pregnancy (odds ratio, 0.86; 95% confidence interval, 0.54, 1.35). However, among those with any cannabis use, frequent use (vs minimal use) was associated with higher odds of hypertensive disorders (odds ratio, 3.44; confidence interval, 1.40, 8.43).

Conclusions: Identifying cannabis use frequency during pregnancy can help identify maternal risk of hypertensive disorders.