Evaluation of the impact of marijuana use on semen quality: a prospective analysis

Aims: To assess if marijuana consumption – prevalent among men of reproductive age and becoming widespread due to decriminalization – is associated with changes in semen parameters. Marijuana’s active metabolite, tetrahydrocannabinol, can alter signaling pathways within spermatozoa, affecting spermatogenesis and fertility. Methods: We prospectively evaluated semen analyses (SA) from men presenting for infertility evaluation at one institution from July 2017 to April 2018. Participants completed a reproductive health questionnaire including items regarding marijuana consumption. SA was performed in accordance with World Health Organization (WHO) 5th Edition criteria. SA parameters included volume (ml), concentration (million/ml), motility (%), progressive motility (%), and Tygerberg strict morphology (%). Results: A total of 409 patients completed the questionnaire; 174 (43%) men reported marijuana use (ever-users). Current and past users comprised 71 (17%) and 103 (25%), respectively. Compared with never-users, current and past users had a significantly higher likelihood of abnormal sperm strict morphology (33.1% versus 50.7% and 53.4%, respectively; p  < 0.001). However, sperm motility was more likely to be less than WHO reference values in never-users than current and past-users (38.3% versus 21.1% and 27.2%, respectively; p  = 0.01). In multivariate logistic regression analyses, current use was associated with increased odds of abnormal strict morphology [odds ratio (OR) 2.15, 95% confidence interval (CI): 1.21–3.79] and semen volume less than WHO reference value (OR 2.76, 95%CI: 1.19–6.42), while odds of less than WHO reference value sperm motility were reduced (OR 0.47, 95%CI: 0.25–0.91). Conclusion: Marijuana use is common among men presenting for fertility evaluation, and may have a detrimental effect on semen quality, particularly morphology and volume, but may be protective against abnormal sperm motility. Large, prospective studies of both semen quality and fertility in this growing, at-risk population are warranted.