Please use this link to access this publication. ABSTRACT Objective There is limited evidence of the impact of cannabis legalization on the prevalence of cannabis use and use of other substances. The aim of this exploratory observational study was to compare rates of cannabis use, cigarette smoking, alcohol consumption, and the use of any street drugs during the preconception period and in pregnancy in two convenience samples of pregnant persons in British Columbia, Canada, before and after the legalization of cannabis. Methods Any pregnant person residing in British Columbia, aged >19 years, at any gestational age was eligible to participate. Pre- and post-legalization study participants were recruited between May and...