The Impact of Chlamydia trachomatis on Male Infertility: A Systematic Review and Meta-Analysis

Abstract

Background Chlamydia trachomatis (CT) is a common sexually transmitted infection, yet its contribution to male infertility remains incompletely understood. Methods A systematic review and meta-analysis of case-control studies were conducted following PRISMA guidelines. Literature from PubMed/MEDLINE, Scopus, Cochrane, and Embase (2000 onward) was screened. Random-effects models were used in R, with subgroup analyses by geography, case definition, diagnostics, and matching criteria. Results Out of 2941 records, 26 case-control studies (11 706 participants) met inclusion criteria. Most studies used molecular diagnostics (n = 23). A significant association was found between CT infection and male infertility (odds ratio [OR] 3.68 [95% CI 2.24-6.02]), with substantial heterogeneity (I2 = 65%). Age-matched studies showed higher effect sizes (OR 6.77), and publication bias was detected (trimmed OR 2.75). Conclusions While findings suggest that CT infection may impair male fertility, confounding, bias, and the lack of geographical representativeness limit inference. High-quality, large-scale prospective studies are needed to confirm causality and guide targeted interventions.