Modes of prenatal cannabis use and associations with anxiety, depression, and alcohol and nicotine use

Background Prior studies have shown associations of prenatal cannabis use with psychiatric conditions and co-occurring substance use, but most characterize cannabis use as binary or frequency-based. To capture heterogeneity in cannabis use patterns, this study examined associations between modes of prenatal cannabis use and anxiety, depression, and non-cannabis substance use. Methods Pregnant patients were universally screened for cannabis use during pregnancy in a large integrated health system from January 2021 through December 2024. Cannabis modes included smoking, vaping, dabbing, edibles, and topicals. Prenatal anxiety and depressive disorders were identified using ICD-10-CM codes, and self-reported alcohol, e-cigarette/vaping, and other tobacco use since pregnancy were assessed at entrance to prenatal care. Modified Poisson regression models estimated associations between cannabis modes and psychiatric and non-cannabis substance use outcomes. Results Among 179,727 pregnancies, 3.7% reported prenatal cannabis use (2.6% reported smoking, 1.2% edibles, 0.9% vaping, 0.3% dabbing, and 0.2% topicals). Most modes were associated with anxiety and depression, with larger associations observed for edibles, vaping, and topicals. Edibles had the strongest association with alcohol use, while inhaled modes (i.e., smoking, vaping, dabbing) were more strongly associated with e-cigarette/vaping and other tobacco use. In frequency-stratified sensitivity analyses, associations were generally observed across both daily/weekly and monthly-or-less cannabis use. Conclusion Modes of prenatal cannabis use were differentially associated with psychiatric disorders and non-cannabis substance use. Assessing mode of administration in addition to frequency may help identify patients who could benefit from further assessment of psychiatric symptoms and co-occurring alcohol or nicotine use.