Clinical Evaluation of Sperm DNA Fragmentation and Its Influence on Male Infertility and Assisted Reproductive Technology Outcomes Using the TUNEL Assay

Background: Male factors contribute to approximately 50% of infertility cases, however, conventional semen analysis does not detect molecular sperm abnormalities. Sperm DNA fragmentation (SDF) is crucial in fertilization, embryo development, and pregnancy outcomes. However, its impact on assisted reproductive technology (ART) success remains unclear. Aim: This study aims to investigate the clinical significance of SDF in ART outcomes and its potential as a biomarker for male infertility. Methods: This prospective study included 180 infertile males. Semen analysis was performed as per World Health Organization 2021 guidelines, sperm morphology was assessed using Diff-Quik staining and a TUNEL assay with flow cytometry to evaluate SDF. Based on semen parameters and SDF levels, participants underwent either in vitro fertilization (IVF, n = 59) or intrauterine insemination (IUI, n = 121). Pregnancy outcomes were assessed using beta-human chorionic gonadotropin levels and ultrasound. Results: Significant differences in semen parameters and SDF levels were observed between IVF and IUI groups ( P < 0.05). IVF had higher pregnancy rates, with a negative correlation between SDF and conception success. Elevated SDF (>20% human chorionic gonadotropin) was associated with lower ART success. Lifestyle factors, including smoking (34.5%) and multiple substance use (35.6%), significantly increased SDF levels ( P = 0.0001). Conclusion: SDF correlates with altered semen parameters and ART success, with lower SDF linked to improved IVF outcomes. Although a similar trend was observed in IUI, the association was not statistically significant. Lifestyle factors and paternal age significantly influenced SDF. SDF assessment can enhance the evaluation of male infertility and ART success.