Trends in perception of risk of regular marijuana use among US pregnant and nonpregnant reproductive-aged women.

Objective Marijuana use may pose risks for reproductive and perinatal health. 1,2 Marijuana use among pregnant and reproductive-aged women increased 62% in the last decade. 3 Our objective was to investigate time trends in perception of risk of regular marijuana use among U.S. pregnant and non-pregnant reproductive-age women. Study Design We analyzed National Survey on Drug Use and Health (NSDUH) data from 2005-2015, a nationally representative survey on substance use in the civilian, non-institutionalized U.S. population. 4 Data were collected using computer-assisted self-interviewing techniques to maximize privacy and confidentiality. We included female respondents ages 18-44 who were pregnant (unweighted N=8,713) or not pregnant (unweighted N=161,902). Respondents were asked: "How much do people risk harming themselves physically and in other ways when they smoke marijuana once or twice a week?" Possible responses included "No risk", "Slight risk," "Moderate risk," "Great risk", or "Don't Know." We calculated time trends in respondents answering "No risk." We used logistic regression to examine annual changes in the perception of no risk of regular marijuana use, adjusted for age, race/ethnicity, education, pregnancy status, and marijuana use within the prior 30 days. Average predicted probabilities of perceiving no risk of regular marijuana use were derived from regression models to show adjusted changes in risk perception over time among pregnant and non-pregnant women, by marijuana use status. Analyses were weighted to account for the complex survey design. The NSDUH are deidentified, publicly available data, and this study did not require IRB approval. Results The average predicted probability of reporting no risk of regular marijuana use among all women increased from 4.6% in 2005 (95% CI: 4.2,5.0) to 19.0% in 2015 (95% CI: 18.3,19.7). Among women who did not report marijuana use in the prior 30 days, the average predicted probability of reporting no risk of regular marijuana use increased from 3.5% (95% CI: 3.0,3.9) to 16.5% (95% CI: 14.9,18.1) among pregnant women and from 3.1% (95% CI: 2.8,3.4) to 14.8% (95% CI: 14.0,15.5) among non-pregnant women (Figure). Among women who reported marijuana use in the prior 30 days, the average predicted probability of reporting no risk of regular marijuana use increased from 25.8% (95% CI: 23.0,28.7) to 65.4% (95% CI: 62.5,68.4) among pregnant women and from 23.7% (95% CI: 21.8,25.6) to 62.6% (95% CI: 61.0,64.3) among non-pregnant women. The probability of women reporting no risk of daily cigarette smoking also increased over time (1.1% in 2005 vs. 3.4% in 2015; data not shown), although this increase was far smaller than that observed for marijuana use. Conclusion Perception that regular marijuana use has no risk has increased threefold from 2005-2015 among U.S. reproductive-age women. Pregnant and non-pregnant women who used marijuana in the prior 30 days more commonly perceived that regular use had no risk, relative to women who had no such marijuana use. However, perception that regular marijuana use has no risk increased even among women without marijuana use in the prior 30 days. We relied on self-reported marijuana use, which might underestimate the true prevalence. Women were asked about perception of risk of marijuana use generally, and not specifically about perinatal marijuana use. As 30 states have laws permitting medical or recreational marijuana, it is important to understand patterns in women's perceptions of the risks of regular marijuana use. Findings support the importance of investigating the effects of marijuana use on reproductive health.