Ever cannabis use and biomarkers of male fecundity – A study in the Danish National Birth Cohort

Background Reports of low semen quality have led to investigations of potential risk factors, including cannabis use. Cannabis affects the endocannabinoid system, which in part regulates spermatogenesis and hormonal balance, but evidence on its impact on male reproductive health remains inconsistent. Objective This study examined the associations between ever cannabis use and biomarkers of male fecundity in a large cohort of young Danish men incorporating detailed information on their concurrent health behaviors and potential confounding factors during fetal life, a key limitation of previous studies. Methods We used data from the Fetal Programming of Semen Quality cohort, a sub cohort of 1058 young men born to women enrolled in the Danish National Birth Cohort. Cannabis use was self-reported via an online questionnaire before a clinical examination. Semen samples were collected and analyzed for volume, concentration, total count, motility, morphology, and DNA fragmentation. Hormone levels were measured from venous blood samples. Testicular volume was self-assessed using a Prader Orchidometer. Results Among participants included in the analytical sample, 324 (31 %) had never used cannabis and 721 (59 %) had used cannabis at least once. We observed no association between ever cannabis use and male fecundity biomarkers, except for a slight indication of higher follicle-stimulating hormone (FSH) levels among ever cannabis users (8 % [95 % CI: −2, 20]). Conclusion While we found no associations between ever cannabis use and most biomarkers of fecundity in young men, the higher FSH levels among ever cannabis users could suggest early signs of impaired testicular function. However, this needs to be confirmed in studies with a more comprehensive assessment of cannabis exposure. ; Background: Reports of low semen quality have led to investigations of potential risk factors, including cannabis use. Cannabis affects the endocannabinoid system, which in part regulates spermatogenesis and hormonal balance, but evidence on ...