Correlation between sperm parameters and sperm DNA fragmentation in fertile and infertile men

Background: It is established that sperm DNA integrity is essential in fertilization and normal embryo and fetal development. Routine semen analysis gives an approximate evaluation of the functional competence of spermatozoa, but does not always reflect the quality of sperm DNA. Therefore, the evaluation of sperm DNA integrity, in addition to routine sperm parameters, could add further information on the quality of spermatozoa and reproductive potential of males. Objective: The objective of this study was to determine the levels of sperm DNA damage in fertile and infertile males and its correlation with semen parameters. Materials and Methods: Semen samples were collected from 45 infertile men selected from couples attending the infertility clinic with a history of infertility of ≥1 years and 75 healthy volunteers of proven fertility (initiated a successful pregnancy) served as the control group. After routine sperm analysis, DNA damage was determined using single cell gel electrophoresis (comet) assay method. Results: The mean of DNA damage (comet value) in the sperms of infertile males was significantly higher than that of fertile males (12.9±7.59 vs. 48.77±24.42, p<0.001). A significant negative correlation was observed between DNA damage and sperm motility in fertile group (p<0.02, R=-0.263). In infertile males, significant negative correlations were observed between DNA damage with sperm motility (p<0.002, R=-0.45) and morphology (p<0.03, R=-0.317). There was no significant correlation between sperm concentration and sperm DNA damage in both groups. Conclusion: These results indicate that sperm DNA damages in infertile males is significantly higher than fertile males and sperms with abnormal morphology and low levels of motility has more abnormal DNA damages than motile and normal sperms.