Detection of DNA fragmentation in human spermatozoa: correlation with semen parameters.

To determine the prevalence of high levels of sperm DNA damage among infertile men with normal and abnormal semen parameters, 90 patients were subdivided into the following three groups. Group A (n = 30): men with normal semen parameters who acted as the controls. Group B (n = 30): asthenozoospermic men and group C (n = 30): teratozoospermic men, suffering from male infertility. DNA damage was evaluated by the rate of DNA fragmentation index (DFI) as assessed by the terminal desoxynucleotidyl transferase-mediated dUTP nick-end labelling assay. It was found that the difference was not significant between the percentage of DFI in patients with asthenozoospermia and the normospermic men (9.46% +/- 8.68 and 8.19 +/- 6.84 respectively, P-value not significant). The patients with teratozoospermia showed a significantly higher percentage of DNA fragmentation compared with the controls (respectively 21.37 +/- 17.26% and 8.19 +/- 6.84%, P < 0.001). There was a positive correlation between abnormal sperm morphology and the DFI (r = 0.44, P < 0.01) in group C. It is concluded that the impairments of sperm parameters were associated with an increase of DNA fragmentation; this association was strictly related to atypical forms.