Association between seminal and serum iron parameters and male infertility: a systematic review and meta-analysis.
BACKGROUND: Iron is an essential trace element for normal spermatogenesis, yet excessive iron accumulation may impair male fertility. Preliminary studies imply a link between elevated iron levels and male infertility, but evidence remains limited without systematic quantitative synthesis. This metaanalysis assessed the association between iron concentrations and male infertility. METHODS: We systematically searched PubMed, CBM, CNKI and Cochrane Library. RevMan, Stata and R were used for data analysis. Randomeffects models pooled effect sizes, with forest and funnel plots generated to evaluate seminal and serum iron levels in male infertility. RESULTS: After screening studies published up to April 2025, a total of ten eligible articles involving 985 participants were finally included in this meta-analysis. Pooled results revealed that seminal and serum iron concentrations were notably higher in infertile males compared with fertile controls. Specifically, infertile men presented higher seminal iron levels (SMD = 0.44, 95% CI: 0.12-0.76, P < 0.05), as well as elevated serum iron levels (SMD = 3.77, 95% CI: 1.68-5.87, P < 0.05). The present results suggest that increased seminal and serum iron concentrations may be potentially correlated with male infertility risk.