DNA damage in prepared semen is associated with fertilisation rate in assisted reproduction technology (ART) treatment

Abstract

Abstract Purpose This study aims to determine to what extent sperm DNA damage is associated with semen quality and assisted reproduction technology (ART) treatment outcomes. Methods 105 male partners of couples attending for infertility treatment were recruited and DNA integrity was measured by a neutral Comet assay and N7-methyldeoxyguanosine (N7-MedG) DNA levels by an immunoslotblot in sperm prepared by density gradient centrifugation for treatment use. Associations between measures of DNA damage (%tail DNA, proportion of sperm with either low (LDD) or high (HDD) levels of DNA damage, and N7-methylguanine levels), semen quality (concentration and motility) and ART outcomes (% oocytes fertilised, % embryo fragmentation, % cleavage, and birth outcome) were assessed. Results In the prepared sperm samples, DNA damage was significantly associated with semen quality and was lower than that in the original neat sample. % fertilisation was significantly negatively associated with N7-MedG levels, %HDD and % tail DNA and was positively associated with %LDD. % cleavage and live birth in fresh cycles were not associated with DNA damage but there was evidence that %LDD was lower, and %HDD higher, in couples with live births after a frozen embryo transfer cycle. Conclusion DNA damage can negatively impact on semen quality and fertilization rate but not embryo cleavage or live birth rate. These results suggest that the impact of sperm DNA damage on pregnancy outcomes appears in the early stage of embryo development.