Correlation between DNA defect and sperm-head morphology

The utility of sperm DNA testing remains controversial. However, it may be helpful in couples with unexplained failures of multiple assisted reproductive techniques and/or recurrent abortions. This study analysed 10,400 spermatozoa of 26 patients for sperm-head morphology with high-magnification microscopy, DNA fragmentation and sperm chromatin decondensation. A significant negative correlation was demonstrated between sperm-parameters and abnormal sperm-head morphology as assessed by high magnification (score 0 according to this study’s classification): concentration (r = −0.41; P = 0.03), motility (r = −0.42; P = 0.03), morphology (r = −0.63; P = 0.0008). No correlation was found with DNA fragmentation. However, the sperm chromatin-decondensation rate of score-0 spermatozoa was twice as high as the controls (19.5% versus 10.1%; P < 0.0001). This observation suggests that score-0 spermatozoa should not be selected for intracytoplasmic sperm injection.We analysed 10,400 spermatozoa of 26 patients for sperm head morphology at high magnification, DNA fragmentation and sperm chromatin decondensation. We demonstrated a significant negative correlation between sperm parameters: concentration (r = –0.41; P = 0.03), motility (r = −0.42; P = 0.03), morphology (r = –0.63; P = 0.0008) and abnormal sperm head morphology as assessed by high magnification (score 0 according our classification). No correlation was found with DNA fragmentation. The sperm chromatin decondensation rate of score-0 spermatozoa was twice as high as than in controls (19.5% versus 10.1%; P < 0.0001). No significant relationship with sperm DNA fragmentation was observed. We suggest that high-magnification sperm selection could be an important step and a new tool for the clinician, who could decide to discard score-0 spermatozoa with a high risk of abnormal chromatin and select the best sperm cells for intracytoplasmic sperm injection.