Quantitation by image analysis of global DNA methylation in human spermatozoa and its prognostic value in in vitro fertilization: a preliminary study.

OBJECTIVE To determine the relationship between sperm DNA methylation level and sperm characteristics and pregnancy rates. DESIGN Prospective study. Quantitation by image analysis of DNA methylation in sperm nucleus. SETTING Department of Reproduction Biology, Edouard Herriot Hospital, Lyon, France. PATIENT(S) Infertile couples undergoing IVF-ET. INTERVENTION(S) The immunostaining of 5 methyl-cytosine was performed on the spare sperm suspension that was used for an assisted reproduction technology procedure. MAIN OUTCOME MEASURE(S) Sperm characteristics according to World Health Organization criteria, sperm motility parameters with computer-assisted semen analysis, sperm DNA methylation level, and heterogeneity index (HI). RESULT(S) Sperm DNA methylation level and HI are correlated with sperm DNA characteristics. HI is negatively correlated with fertilization rate; sperm DNA methylation level is correlated with pregnancy rate. CONCLUSION(S) The DNA methylation level in human spermatozoa could be a new approach to evaluating the ability of spermatozoa to fertilize and lead to normal embryo development.