Correlation between DNA defect and sperm-head morphology

Abstract

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.