Research from the University of Toronto indicates that high levels of cannabis use may adversely affect the chances of successful pregnancy through in vitro fertilization (IVF). The study, led by embryologist Cyntia Duval, examined 1,059 samples of follicular fluid surrounding developing eggs from patients undergoing IVF treatments. Out of these samples, 62 tested positive for tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis.
The findings revealed that immature egg cells, known as oocytes, from fluids with elevated THC levels exhibited a higher likelihood of chromosomal abnormalities. These oocytes also matured more rapidly compared to those from samples devoid of THC. According to pharmacologist Mark Connor from Macquarie University, who did not participate in the research, “The study suggests that consumption of cannabis might affect the outcome of IVF.” He noted that the study did not explore the potential impacts of cannabis on natural conception.
To further investigate, Duval and her team assessed eggs from 24 consenting patients. Consistent with earlier results, unfertilized eggs exposed to THC concentrations above the average exhibited nearly 10 percent more chromosomal errors and matured at faster rates. Researchers acknowledged that the small sample size limited their ability to control for other fertility-related factors, particularly the age of the patients. Today, age remains the most significant risk factor for diminished egg quality.
Alex Polyakov, an obstetrician and gynecologist at University of Melbourne, who was not involved in the study, commented, “For women considering or undergoing fertility treatment, this research suggests that cannabis use may compromise reproductive outcomes—not by preventing fertilization, but by reducing the likelihood of producing chromosomally normal embryos.” He emphasized that the euploidy of embryos is crucial for successful implantation and a healthy pregnancy, suggesting that cannabis exposure might extend the time to conception and elevate the risk of IVF failure and miscarriage.
Previous animal studies have indicated that THC exposure negatively affects embryo development. Other human studies have established moderate associations between frequent cannabis use and infertility, underscoring the need for additional research. While medical and recreational cannabis is increasingly utilized for pain relief and mental health benefits, it bears significant health risks, including cognitive impairments and heightened cardiovascular disease risk. Usage during pregnancy is strongly discouraged, and experts advise abstaining during conception for the safest outcomes.
Past research has also identified links between cannabis consumption and male fertility issues, reinforcing recommendations for prospective parents. In a 2021 study, obstetrician Kimberly Ryan and colleagues from Oregon Health & Science University noted, “At this time, no amount of marijuana use during conception or pregnancy is known to be well tolerated, and the limited available evidence suggests that the safest choice is to abstain.”
The findings of this significant study were published in the journal Nature Communications, contributing to the ongoing discourse on the implications of cannabis use in relation to reproductive health. As more individuals consider the role of cannabis in their lives, understanding its potential effects on fertility remains crucial.
