Marijuana and tobacco co-use among a nationally representative sample of US pregnant and non-pregnant women: 2005-2014 National Survey on Drug Use and Health findings

•Co-use of marijuana and tobacco is more common than marijuana-only use among women.•Co-use of marijuana and tobacco is less common than tobacco-only use among women.•Pregnant women who co-use differ from non-pregnant women who co-use.•Co-use during pregnancy is associated with disparities in age, race, and ethnicity.•Co-use during pregnancy is associated with alcohol and other illicit drug use.

BackgroundMarijuana and tobacco are the most commonly used illicit and licit drugs during pregnancy. This study aimed to examine a nationally representative sample of US pregnant women and to: (1) determine the prevalence of past month marijuana and tobacco co-use, (2) identify characteristics that distinguish marijuana and tobacco co-users from users of marijuana only, tobacco only, or neither, and (3) compare characteristics that differ between pregnant and non-pregnant co-users of marijuana and tobacco.MethodsData were obtained from 497,218 US women (8721 pregnant) ages 12-49 who participated in the 2005-2014 National Survey on Drug Use and Health. Prevalence and demographic and substance use characteristics were compared across groups using weighted estimates and chi-squared tests. Multinomial logistic regression identified demographic and substance use correlates of co-use.ResultsCo-use among pregnant and non-pregnant women was significantly more prevalent than marijuana-only use but was less common than tobacco-only use. In unadjusted frequencies, pregnant co-users significantly differed from non-pregnant co-users across several domains. Among pregnant women, multivariate correlates of co-use of tobacco and marijuana vs. tobacco-only use were ages 12-17, non-Hispanic black race, Hispanic ethnicity, and past month polytobacco, any alcohol, and other drug use (all adjusted odds ratios ≥ 2.0).ConclusionsIn this first examination of the prevalence and correlates of co-use of marijuana and tobacco among a nationally representative group of pregnant women, pregnant co-users were more likely to report other high risk behaviors compared with non-pregnant co-users and users of a single substance, suggesting disparities worthy of further investigation.