Higher Marijuana use among Young Adults Persists Even during Pregnancy.

Background: Marijuana is linked to adverse pregnancy health effects, yet limited data exist regarding demographic and regional differences in marijuana use during pregnancy. Objective: To determine the prevalence of prenatal marijuana use among reproductive-age women and assess regional and age-related differences. Methods: This study secondarily analyzed cross-sectional, population-based Pregnancy Risk Assessment Monitoring System data from states querying about marijuana use. It included 10,350 women with live births in 2009-2011. Primary outcome was "any use of marijuana" during pregnancy. Logistic regression analysis examined associations between marijuana use, age, and other socio demographic characteristics. Results: In all states, marijuana use during pregnancy was more likely in adolescent and young adults (AYA; <25 years) than older mothers: Alaska, prevalence rate ratio (PRR), 2.07 (95% confidence interval [CI], 1.5-2.6); Hawaii, PRR, 1.55 (95% CI, 1.2-1.9); Vermont, PRR, 2.44 (95% CI, 1.9-2.9). Regression analyses, controlling for other demographic characteristics, showed that age <25 was associated with higher odds of marijuana use in Alaska (adjusted odds ratio [aOR], 2.24 [95% CI, 1.9-2.5]) and Vermont (aOR, 1.74 [95% CI, 1.5-1.9]). Smoking cigarettes during pregnancy was associated with higher odds of concomitant marijuana use in Alaska (aOR, (P<0.05)) and Vermont (aOR, 1.2 (P<0.05)). Conclusions: AYA reported higher marijuana use rates during pregnancy than older women. Cigarette use during pregnancy was associated with marijuana use. Additional research, examining national marijuana use patterns and maternal and child health outcomes in the context of evolving marijuana policies, is warranted.