Abstract Importance: Many studies have evaluated whether in utero cannabis exposure is associated with fetal and neonatal outcomes, yet little is known about whether prenatal cannabis use is associated with maternal health outcomes during pregnancy. Objective: To evaluate whether prenatal cannabis use is associated with maternal health outcomes during pregnancy. Design, setting, and participants: This population-based retrospective cohort study included pregnancies in Northern California from January 2011 to December 2019 that lasted 20 weeks or longer and were screened for prenatal cannabis use. Exposures: Prenatal cannabis use was defined as any self-reported use during early pregnancy or a positive toxicology test result based on universal screening at entrance...