Please use this link to access this publication. Abstract Objective This study aimed to assess the impact of cannabis legalization on both qualitative and quantitative umbilical cord tissue tetrahydrocannabinol (THC) rates and concentrations as a proxy for fetal exposure. Study Design This is a retrospective, observational study of umbilical cord tissue THC levels in a single center, comparing THC exposure rates and concentration levels before and after cannabis legalization in the state of Illinois, Epoch 1 (October 1, 2018–June 30, 2019, pre-legalization) and Epoch 2 (July 1, 2019–August 31, 2021, post-legalization). Results A total of 811 umbilical cords were analyzed during epoch 1 and...