Sperm DNA Fragmentation Index, Semen Quality, and Assisted Reproductive Technology Outcomes: A Systematic Review and Meta‐analysis of Observational Studies

BACKGROUND: Sperm DNA fragmentation index (DFI) reflects nuclear DNA damage, but its association with assisted reproductive technology (ART) outcomes remains controversial. OBJECTIVES: This meta-analysis evaluated associations between DFI, semen parameters, and ART pregnancy outcomes. METHODS: Four databases were searched through September 2025 for studies comparing reproductive outcomes between low- and high-DFI groups. Random-effects models pooled risk ratios (RRs) or weighted mean differences with 95% confidence intervals (CIs). Subgroup, sensitivity, and publication bias analyses were conducted. RESULTS: Eighty-seven studies were included. Low DFI was associated with higher clinical pregnancy rate (RR = 1.121, 95% CI:1.068-1.178), live birth rate (RR = 1.136, 95% CI:1.063-1.215), and embryo implantation rate (RR = 1.198, 95% CI:1.085-1.323), and lower miscarriage risk (RR = 0.731, 95% CI:0.652-0.820). No significant association emerged for biochemical pregnancy rate. After publication bias adjustment, clinical pregnancy and live birth associations lost significance, while embryo implantation and miscarriage associations remained robust. Semen parameters favored the low-DFI group. CONCLUSION: DFI may serve as a supplementary indicator to routine semen analysis, providing information on sperm DNA integrity to complement the assessment of semen quality and ART reproductive outcomes; however, the current evidence primarily reflects population-level associations, and its routine clinical utility remains to be further clarified. CLINICAL TRIAL REGISTRY: Registration number: CRD420261356371.