Tobacco and Cannabis Use During and After Pregnancy in California.

Objectives: As the social and legal acceptance of cannabis use grows, health professionals must understand and mitigate the impact of cannabis use in the perinatal period. Here we compare the prevalence of tobacco and cannabis use during and after pregnancy in California, a state that recently legalized cannabis use.

Methods: Measures of tobacco and cannabis use during and after pregnancy were obtained from California's Maternal and Infant Health Assessment, an annual population-based survey of California resident women with a live birth. To allow analysis of county-level variation, we pooled data from the 35 counties with the largest numbers of births from 2017 to 2019.

Results: Cannabis use was more than twice as common as cigarette smoking among pregnant women (4.9% vs. 2.1%) in California. This difference was even more pronounced in some counties; for example, in Los Angeles, cannabis use was four times more prevalent than cigarette use. Either during or soon after birth, 7.3% of women in California reported cannabis use. Of those who smoked tobacco cigarettes prior to pregnancy, 73% quit before their third trimester of pregnancy, though 33.0% of these women reported a post-partum relapse in cigarette use.

Conclusions: States that have legalized cannabis must attend to the increasing prevalence of perinatal cannabis use, as well as concurrent use with tobacco and other substances. Efforts to support cannabis cessation should draw from successful public health approaches in tobacco control.