“The present study investigated the effect of the lack of CB1 and CB2 receptors in mice ovarian morphology, folliculogenesis, oocyte retrieval, and oocyte maturation and evaluated the use of Δ9-tetrahydrocannabinol (THC) on oocyte in vitro maturation (IVM) by comparing classical IVM and two-step IVM by analyzing the meiotic competence of the oocytes and their evolution toward embryos.
Thus, when CB1 and CB2 receptors were missed, the ovary area and volume was significantly less and the action of the equine chorionic gonadotropin (eCG) hormone was diminished.
In addition, the mutant genotypes had fewer ovarian follicles and they were less competent after eCG administration compared with wild-type mice, and this lack of CB receptors showed a mismatch of oocyte maturation.
However, the in vitro use of THC showed improvements in oocytes IVM after a Pre-IVM step for 48 hr, as those oocytes reached a significantly higher polar body rate, a larger diameter and the best result on blastocysts rate was achieved when THC was used during the IVM step.”
https://www.ncbi.nlm.nih.gov/pubmed/32198753
https://onlinelibrary.wiley.com/doi/abs/10.1002/jcp.29663