Cannabis and Male Fertility: A Systematic Review.
Level 4 - case-series / case-control
Systematic review summarizing predominantly observational human studies and animal research rather than randomized trials.
PubMed 30916627 · doi:10.1097/JU.0000000000000248
What was done
The authors conducted a systematic literature search in PubMed/MEDLINE to evaluate published research on the effects of cannabis on male fertility, focusing on semen parameters, reproductive hormones, and reproductive anatomy across human and animal studies.
What was found
The abstract reports no numerical values, effect sizes, or confidence intervals. Summarized qualitative findings indicate that cannabis exposure is associated with decreased sperm count and concentration, reduced sperm motility and viability, abnormal morphology, and inhibited capacitation and fertilizing capacity. Endocrine effects were mixed: testosterone findings were inconclusive, luteinizing hormone was reduced, and follicle-stimulating hormone was unchanged. Testicular atrophy and reduced libido reported in animal models have not been replicated in humans.
Why it matters
As cannabis use becomes more prevalent among reproductive-aged men, these findings highlight potential negative effects on semen quality relevant to fertility counseling and clinical workups.
Limits
The abstract provides no study counts, participant sample sizes, formal meta-analytic estimates, or risk-of-bias evaluations. Evidence in humans is largely observational and subject to confounding, and certain severe reproductive outcomes remain restricted to animal models.
Cited by
- partial Cannabis use impairs sperm production, decreases testosterone, and increases sperm DNA fragmentation, leading to higher miscarriage rates in female partners.