Cannabis and Male Fertility: A Systematic Review.

Purpose: With cannabis consumption on the rise and use prominent among males of reproductive age it is essential to understand the potential impact of cannabis on male fertility. We reviewed the literature regarding the effects of cannabis on male fertility. Materials and Methods: We performed a literature search using PubMed (R)/MEDLINE (R) to identify relevant studies of the effects of cannabis on male fertility. Relevant studies were identified and reviewed. Results: The strongest evidence of cannabis induced alterations in male fertility is in the category of semen parameters. Research supports a role for cannabis in reducing sperm count and concentration, inducing abnormalities in sperm morphology, reducing sperm motility and viability, and inhibiting capacitation and fertilizing capacity. Animal models demonstrate a role for cannabis in testicular atrophy, and reduced libido and sexual function but to our knowledge these results have not yet been replicated in human studies. Studies of hormonal changes suggest inconclusive effects on testosterone levels, lowered luteinizing hormone levels and unchanged follicle-stimulating hormone levels. Conclusions: Current research suggests that cannabis may negatively impact male fertility. Further studies are needed to validate that robust findings in animal models will carry over into human experience. Clinicians should be aware of these potential effects when prescribing medical marijuana therapies to men of reproductive age, and they should consider the degree of cannabis use as a possible component of a complete male infertility workup.