Associations Between Recreational Cannabis Legalization and Disparities in Prenatal Tobacco and Cannabis Use

Abstract Introduction Although prenatal cannabis use is rising, whether recreational cannabis legalization is driving changes in use of both cannabis and tobacco use remains unknown. We evaluated the associations between legalization and tobacco and cannabis use during pregnancy overall and across demographic and higher-risk strata. Methods We linked data on 95,569 women from 21 states and DC who participated in the 2016-2021 Pregnancy Risk Assessment Monitoring System, which collected self-reported tobacco and cannabis use during pregnancy, with state recreational cannabis legalization and retail sales availability. Using difference-in-differences multinomial logit regression models, we examined the associations between recreational cannabis legalization and tobacco and cannabis use overall and by demographic (race and ethnicity, education, age) and higher-risk (pre-pregnancy depression, pre-pregnancy alcohol use) strata, with demographic and policy controls and state and year fixed effects. Results While prenatal tobacco-only use declined from 8.5% to 5.4% from 2016 to 2021, tobacco and cannabis use remained relatively stable at 2.4% and cannabis-only use at 3.4%. Recreational cannabis legalization was associated with increases in cannabis-only use (aRRR 1.45; 95% CI: 1.05, 1.99) and tobacco and cannabis use (aRRR 1.42; 95% CI: 0.96, 2.10). The start of retail sales was also associated with increases in cannabis-only use (aRRR 1.91; 95% CI: 1.41, 2.60) and tobacco and cannabis use (aRRR 1.48; 95% CI: 1.02, 2.14). There was some evidence of increases in cannabis-only use post-legalization and post-retail sales among White women and those who reported light and moderate/heavy alcohol use. Conclusions Recreational cannabis legalization and the introduction of retail sales were associated with increases in cannabis-only use and tobacco and cannabis use during pregnancy. Implications We evaluated the associations between recreational cannabis legalization and tobacco and cannabis use during pregnancy and found that cannabis-only use and use of both substances increased post-legalization and post-retail sales availability. These findings highlight the importance of screening for both tobacco and cannabis use in clinical settings and through population-level surveillance. Continued monitoring of cannabis legalization’s public health impacts is critical to guide targeted outreach and prevention strategies to address substance use during pregnancy.