The Effect of Marijuana on the Incidence and Evolution of Male Infertility: A Systematic Review

Over the past decade, the consumption of marijuana or any other form of cannabis, whether medically, recreationally, or illegally, has been escalating worldwide. The additive effect of marijuana and the easy availability could make this increasing trend possible for imperceptible outcomes affecting one's physiology on multiple levels. The rationale of this review is to study and enumerate several effects marijuana may have on male reproductive organs, especially in men who are dealing with subfertility or infertility issues. A literature search was done from September 1, 2021, to September 14, 2021, using the following databases: PubMed, Google Scholar, Bielefeld Academic Search Engine (BASE), University of California, Santa Barbara Library, and PubMed Central. The studies included in this review comprised systematic reviews, cross-sectional, case-control, cohort, and longitudinal studies published during 2010-2021 in the English language. After an extensive review of all studies, the quality was assessed using appropriate quality appraisal tools, and 15 eligible reports were identified and included. In-depth research on the final studies concluded that marijuana seems to have specific adverse effects on the sperm parameters, namely, sperm count, concentration, motility, morphology, capacitation, and viability, thus affecting fertility in men. Certain hormone levels, including testosterone, luteinizing hormone, and follicle-stimulating hormone, also drew attention, potentially impacting men's fertility; however, a finite inference could not be substantiated by the studies. Although the studies show significant effects in sperm parameters and organic sexual dysfunction, it is also to be noted that these studies are observational only and are conducted in small groups in multicenter geographical locations where other lifestyle patterns could be confounding. Given this restriction, it is suggested that further human trials on a larger scale be conducted to provide an even more concrete conclusion, especially after considering other factors that may affect the generalization of these trials.