Marijuana and (In)Fertility

Marijuana consumption is prevalent among men of reproductive age, and decriminalization in the United States is growing as the medical use of marijuana is legal in 33 states and recreational use is legalized in 10 states, including Washington, with no signs of slowing down.

It is estimated that 192 million individuals, comprising 2.5% of the world population, reported use of marijuana in 2016, making it the most used drug worldwide. According to the National Institute of Health, approximately 22 million Americans currently partake in marijuana use, with 30% of marijuana consumers meeting criteria for a substance use disorder.

What many consumers don’t know is that marijuana and its active metabolite, tetrahydrocannabinol (THC), can alter signaling pathways within spermatozoa thereby affecting spermatogenesis and fertility, increasing the demand for a better understanding of the potential impacts of TCH on general and reproductive health as well as public policy and global healthcare.

University of Washington Men’s Health Clinic Director Dr. Thomas Walsh and his team of researchers set out to begin to answer these questions in evaluating the impact of marijuana use on semen quality from men presenting for infertility evaluation at the Men’s Health Center over a nine-month period.

Participants completed a reproductive health questionnaire including items regarding marijuana consumption. Semen Analysis (SA) was performed in accordance with WHO 5th Ed (2010) criteria. SA parameters included volume (mL), concentration (million/mL), motility (%), progressive motility (%), and Tygerberg strict morphology (%).

Of the 409 patients who underwent SA and completed the questionnaire 43% of them reported marijuana use (ever-users). Current and past users comprised (17%) and (25%) individuals, respectively.

Compared to never-users, ever-users had a significantly higher likelihood of abnormal sperm morphology, however, sperm motility was less likely to be abnormal in ever-users. In multivariate logistic regression analyses, current marijuana use was associated with increased odds of abnormal strict morphology (OR 2.15, 95%CI: 1.21-3.79) and semen volume (OR 2.76, 95%CI: 1.19-6.42), while odds of abnormal motility were reduced (OR 0.47, 95%CI: 0.25-0.91).

These results among men presenting for fertility evaluation show that marijuana use is a common similarity they share and that may have a detrimental effect on semen quality, particularly morphology and volume, but may be protective against abnormal semen motility.

Acknowledgements: Marah C. Hehemann, Omer A. Raheem, Saneal Rajanahally, Sarah Holt, Tony Chen, Kelly Song, Heather Rylander, Emma Chow, Kevin A, Ostrowski, Charles H. Muller