A new animal study, to be presented at ENDO 2020, shows that when female eggs are exposed to THC, it can affect their ability to produce embryos that result in viable pregnancies. Researchers exposed and treated female cow eggs with different concentrations of THC that were comparable to both recreational and therapeutic doses. The researchers then classified the eggs into five groups: untreated, control, low THC, mid THC, and high THC.
The scientists measured gene expression as well as the rate of development. They found that the embryos that were exposed to higher concentrations of THC were less likely to reach critical development stages by critical checkpoints, which are important in determining both the quality and development potential for the cow eggs. There was a significant delay in these eggs; the THC led to a decrease in the expression of connexins, which are gap proteins.
Master student Megan Misner, a member of the research lab in the Department of Biomedical Sciences at the University of Guelph in Canada, says that the embryos exposed to TCH are “less likely to proceed past the first week of development, and thus lead to infertility."
The initial research shows 62 genes out of the treated groups responded negatively when exposed to THC, but more research is needed. Cannabis (marijuana) is the most popular recreational drug in the United States, and medical marijuana use is also increasing. As Misner explains, “Currently, patients seeking infertility treatments are advised against cannabis use, but the scientific evidence backing this statement is weak. This makes it difficult for physicians to advise patients undergoing in vitro fertilization properly.”