According to researchers from the Endocrine Society, exposure to tetrahydrocannabinol (THC), which is the primary component of marijuana, can limit the number of viable eggs women have.
“Currently, patients seeking infertility treatments are advised against cannabis use, but the scientific evidence backing this statement is weak,” said researcher Megan Misner. “This makes it difficult for physicians to properly advise patients undergoing in vitro fertilization.”
Fertility risks
The researchers came to their findings after exploring the effect of marijuana on female cows’ eggs. Some of the eggs were treated with a recreational amount of THC, while others were given medical-grade doses of the drug. The researchers then tracked the eggs’ progress, evaluating them at various points to see how exposure to the drug affected their development.
Their study revealed that exposure to THC was not only associated with a reduced likelihood of a fertilized embryo, but the drug was responsible for affecting over 60 genes in the treated eggs.
“This implies lower quality and lower fertilization capability, therefore lower fertility in the end,” said Misner.
Misner and her team found two other key indicators of a reduced likelihood of infertility: one was the lower number of genes known as connexins, and the other was the eggs’ inability to reach critical developmental stages.
The researchers explained that higher levels of connexins typically predict a higher chance of fertility, while the gradual maturation process of the eggs is key for fertilization. At higher levels of THC exposure, the eggs were less likely to be able to carry out their regular functions.
“This embryo would be less likely to proceed past the first week of development, and thus lead to infertility,” Misner said.