Elimination of apoptotic spermatozoa by magnetic-activated cell sorting improves the fertilization rate of couples treated with ICSI procedure.

Couples with unexplained infertility (UI) tend to have low fertilization rates using current in vitro fertilization procedures. The aim of this study was to evaluate whether elimination of apoptotic spermatozoa could increase the likelihood of pregnancy by intra-cytoplasmic sperm injection (ICSI). A total of 74 couples with UI were divided into two groups including the control group (n = 37) for which spermatozoa prepared by density gradient centrifugation were injected into oocytes and the study group (n = 37) for which spermatozoa was further processed by magnetic-activated cell sorting to eliminate apoptotic spermatozoa, then injected into oocytes. Fertilization, cleavage, pregnancy and birth rates were analyzed in two groups. The fertilization rate was significantly higher in the study group compared with the control group (73.41% vs. 61.11%; p = 0.03). On day 3, the number of eight blastomeric non-fragmented embryos per oocytes was also significantly higher in study group as compared with controls (45.05% vs. 34.16%; p = 0.049). The pregnancy and birth rates were 43.24 and 40.5% in study group and 35.11 and 27% in control group respectively. Statistical analyses showed that the differences in the pregnancy and live-birth rates between study and control groups were not significant (p = 0.37 and 0.16 respectively). These results demonstrate that non-apoptotic spermatozoa display higher fertilization potential and embryo quality following ICSI.