Sperm deoxyribonucleic acid damage in normozoospermic men is related to age and sperm progressive motility

Objective: To evaluate sperm DNA fragmentation in normozoospermic male partners of couples undergoing infertility evaluation. Design: Retrospective cohort study. Setting: Clinical andrology laboratory. Patient(s): A total of 1,974 consecutive normozoospermic men selected from a larger cohort of 4,345 consecutive, nonazoospermic men presenting for infertility evaluation. Intervention(s): None. Main Outcome Measure(s): Clinical parameters, conventional semen parameters, and sperm DNA fragmentation assessed by flow cytometry-based TUNEL assay and reported as percent sperm DNA fragmentation (%SDF). Result(s): The mean (+/- SD) %SDF and the proportion of men with high %SDF (>30%) were significantly lower in the normozoospermic compared with the entire cohort of 4,345 evaluable infertile men (17.6% +/- 10.1% vs. 20.7% +/- 12.4% and 11% vs. 20%, respectively). In the group of 1,974 normozoospermic men, %SDF was positively correlated with paternal age (r = 0.17) and inversely correlated with progressive motility (r = -0.26). In the subset of normozoospermic men with sperm parameters above the 50th percentile (>= 73 x 10(6) sperm/ mL, >= 55% progressive motility, and >= 14% normal forms, World Health Organization 2010 guidelines), 5% (4 of 83) had elevated %SDF (>30%). Conclusion(s): In this large cohort of normozoospermic men presenting for infertility evaluation, DNA fragmentation level is related to sperm motility and paternal age, and 11% of these men have high levels of spermDNAfragmentation. Furthermore, the data indicate that a nonnegligible proportion (5%) of normozoospermic men with high-normal sperm parameters may also have significant sperm DNA fragmentation. (C) 2014 by American Society for Reproductive Medicine.