RESUMO
OBJECTIVES@#As a remedy for the failure of in vitro fertilization (IVF), rescue intracytoplasmic sperm injection (R-ICSI) has been widely carried out, but it has failed to significantly improve the fertilization rate and clinical pregnancy rate. Sperm DNA fragmentation index (DFI) was highly correlated with pregnancy outcome of artificial assisted reproduction. This study aims to investigate the effect of the sperm DFI on the outcome of R-ICSI and the clinical value of R-ICSI.@*METHODS@#This retrospective analysis was conducted among 140 infertile couples receiving R-ICSI in from January 2014 to December 2019. The subjects were assigned into a total fertilization failure (TFF)+low DFI group (R-ICSI after TFF and DFI<30%) (n=63), a TFF+high DFI group (R-ICSI after TFF and DFI≥30%) (n=16), a partial fertilization failure (PFF)+low DFI group (R-ICSI after PFF and DFI<30%) (n=52), a PFF+high DFI group (R-ICSI after PFF and DFI≥30%) (n=9). All transferred embryos were come from R-ICSI. The general clinical data [infertility duration, male age, female age, basal serum level of follicle stimulating hormone (FSH), basal serum level of luteinizing hormone (LH), antral follicle count, endometrial thickness of human chorionic gonadotropin (HCG) day, and eggs] and R-ICSI cycle outcomes (fertilization rate, normal fertilization rate, cleavage rate, good embryo rate, implantation rate, clinical pregnancy rate and live birth rate) were analyzed. In addition, the effect of R-ICSI on the fertilization outcome of conventional IVF total fertilization failure and partial fertilization failure was explored.@*RESULTS@#There was no significant difference in the general clinical data and R-ICSI cycle outcome between the TFF+low DFI group and the TFF+high DFI group (all P>0.05). There was no significant difference in the general clinical data between the PFF+low DFI group and the PFF+high DFI group (all P>0.05). The fertilization rate and normal fertilization rate in the PFF+low DFI group were significantly higher than those in the PFF+high DFI group (85.40% vs 72.41%, 71.90% vs 58.62%, respectively; both P<0.05). However, there was no significant difference in cleavage rate, good embryo rate, implantation rate, clinical pregnancy rate, and live birth rate between the 2 groups (all P>0.05). The R-ICSI cycle of TFF: A total of 79 fresh cycles, 57 fresh transplant cycles, a total of 761 unfertilized oocytes, and 584 M II oocytes were treated with R-ICSI, the fertilization rate was 83.22%, the normal fertilization rate was 75.51%, the cleavage rate was 98.15%, the good embryo rate was 40.74%, the implantation rate was 30.56%, and the clinical pregnancy rate was 43.86%; 29 live births were obtained. The R-ICSI cycle of PFF: A total of 61 fresh cycles, 31 fresh transplant cycles, a total of 721 unfertilized oocytes, and 546 M II oocytes were treated with R-ICSI; the fertilization rate was 83.33%, the normal fertilization rate was 69.78%, the cleavage rate was 97.36%, the good embryo rate was 44.39%, the implantation rate was 25.42%, and the clinical pregnancy rate was 45.16%; 12 live births were obtained.@*CONCLUSIONS@#In the case of partial fertilization failure of IVF, the sperm DFI affects the fertilization rate and normal fertilization rate of R-ICSI; whether it is a TFF of IVF or PFF of IVF, ICSI can be used as an effective remedy way.