Effect of COVID-19 vaccination on semen parameters: A systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational cohort studies
PubMed 36310390 · doi:10.1002/jmv.28263
What was done
A systematic review and meta-analysis searched PubMed, EMBASE, Web of Science, and the Cochrane Library through June 2022. Eligible studies compared semen parameters before and after COVID-19 vaccination or between vaccinated and unvaccinated men, with no restrictions on vaccine platforms or doses. Effect sizes were pooled as mean differences (MD) with 95% confidence intervals (CI) using a random-effects model. Subgroup, sensitivity, and publication bias analyses were performed.
What was found
Across 12 cohort studies comprising 914 participants, comparing vaccinated to unvaccinated men showed no significant differences in semen volume (MD = 0.18 ml, 95% CI -0.02 to 0.38), sperm concentration (MD = 1.16 million/ml, 95% CI -1.34 to 3.66), total sperm motility (MD = -0.14%, 95% CI -2.84 to 2.56), progressive sperm motility (MD = -1.06%, 95% CI -2.88 to 0.77), total sperm count (MD = 5.92 million, 95% CI -10.22 to 22.05), total motile sperm count (MD = 2.18 million, 95% CI -1.28 to 5.63), total progressively motile sperm count (MD = -3.87 million, 95% CI -13.16 to 5.43), or sperm morphology (MD = 0.07%, 95% CI -0.84 to 0.97). Results were consistent across mRNA, viral-vector, and inactivated vaccines. Sensitivity analyses identified two studies contributing to heterogeneity without materially altering effect sizes.
Why it matters
This review provides quantitative reassurance that COVID-19 vaccination does not impair standard semen parameters across multiple vaccine types, directly addressing a common concern underlying vaccine hesitancy in men.
Limits
All included evidence comes from observational cohort designs rather than randomized trials. The pooled sample size is relatively modest at 914 participants across 12 studies. Heterogeneity was present among the studies, and the abstract does not report duration of follow-up or direct clinical fertility outcomes such as conception or pregnancy rates.
Cited by
- supports A study looking at fertility in men found no effect of COVID-19 vaccines on normal sperm parameters including motility.