Prevalence and Perceived Financial Costs of Marijuana versus Tobacco use among Urban Low-Income Pregnant Women.

OBJECTIVE To examine the relative prevalence of marijuana and tobacco use among low-income post-partum women, using self-report, urine, and hair testing data; and to further explore perceptions of the substances among postpartum women by evaluating perceived risk and monetary cost of prenatal marijuana versus tobacco use. METHODS Data from two studies were available for a total of 100 (Study 1) and 50 (Study 2) low-income, primarily African-American post-partum women. Study 1 participants completed brief self-report measures of substance use as well as urine and hair samples; study 2 participants completed a brief opinion survey regarding the risks and monetary costs of prenatal marijuana use. RESULTS In Study 1, the self-reported prevalence of any tobacco or marijuana use in the past three months was 17% and 11%, respectively. However, objectively-defined marijuana use was more prevalent than self-reported tobacco use: 14% tested positive for marijuana by urinalysis, and 28% by hair analysis. Study 2 participants were more likely to believe that there is a safe level of marijuana use during pregnancy, and nearly half believed that using marijuana during pregnancy was less expensive than smoking cigarettes. CONCLUSION Marijuana use may be as or more prevalent than tobacco use among low-income, African-American pregnant women. These findings may in part be attributable to perceptions of roughly equivalent cost and the lack of a clear public health message regarding prenatal marijuana use, combined with growing pro-marijuana advocacy. A broader public health response to address prenatal marijuana use, along with other substances of abuse, is needed.