Abstract Recent changes in legal status and public perception of cannabis have contributed to an increase use amongst women of reproductive age. Concurrently, there is inadequate evidence-based knowledge to guide clinical practice regarding cannabis and its effects on fertility and early embryonic development. This study aimed to evaluate the effects of the primary psychoactive component of cannabis, delta-9 tetrahydrocannabinol (THC), during oocyte maturation, and its impact on the developing embryo. Bovine oocytes were matured in vitro for 24 h under clinically relevant doses of THC mimicking plasma levels achieved after therapeutic (0.032 μM) and recreational (0.32 and 3.2 μM) cannabis use. THC-treated oocytes were assessed for...