Differential Effects of Sperm Deoxyribonucleic Acid Fragmentation Index on Cumulative Live Birth Rate per Complete Cycle Following IVF and ICSI Treatment in Patients Without Severe Male Infertility

BACKGROUND: Infertility impacts 10%-15% of the population, with prominent male contributions. Routine semen analysis fails to fully evaluate male fertility. Sperm DNA fragmentation (SDF) links to poor reproductive outcomes. Although intracytoplasmic sperm injection (ICSI) is recommended for high SDF, its overuse in nonsevere male infertility is controversial. The divergent impacts of SDF on in vitro fertilization (IVF) and ICSI cumulative live birth rate (CLBR) remain unclear. OBJECTIVE: To evaluate the effect of SDF on the CLBR in couples undergoing IVF and ICSI, and to explore the optimal choice of assisted reproductive fertilization methods under different levels of SDF in nonsevere male infertility. MATERIALS AND METHODS: Sperm chromatin structure assay, propensity score matching (PS-matching), generalized additive model (GAM), and causal forest (CF) model analysis. RESULT(S): After PS-matching: 398 cases in both IVF and ICSI groups (standardized difference <0.1). GAM: IVF group's CLBR decreased with DFI; ICSI group had no correlation. IVF's CLBR was higher when DFI < 14.3%, lower when DFI > 47.9%. CF model: DFI was a top predictor; SHAP analysis: DFI < 14.2% favored IVF, DFI > 14.2% favored ICSI. CONCLUSION(S): For nonsevere male infertility, IVF yields superior baseline CLBR at DFI < 14.3%. Rising DFI impairs IVF outcomes, whereas ICSI remains unaffected. Pretreatment DFI enables individualized IVF/ICSI selection.