Time-dependent effects of iatrogenic stress on sperm membrane integrity and DNA fragmentation

Objective: To investigate the time-dependent relationship between sperm plasma membrane integrity (sperm viability) and sperm DNA fragmentation (SDF) following semen liquefaction and incubation at room temperature. Methods: Liquefied semen samples from 30 individuals were diluted with sperm medium and incubated at room temperature for 0, 2, 6, and 24 hours. Results: Sperm viability and SDF were assessed at each time point. Viability declined exponentially over time ( R 2 =0.988), while SDF increased logarithmically ( R 2 =0.989). When the corresponding trend lines were plotted together, a crossover point was observed at approximately 2 hours post-liquefaction; at this time, both viability and SDF values exceeded the reference thresholds typically established when samples are analysed immediately after liquefaction. The decline in sperm viability during the first 6 hours of incubation was significantly more rapid than the increase in SDF. Conclusion: These findings support the hypothesis that loss of sperm plasma membrane integrity may precede and contribute to increased SDF. The potential clinical implications of these findings are discussed.