Intracytoplasmic sperm injection is not associated with poor outcome in couples with normal semen parameters and previous idiopathic fertilization failure in conventional in vitro fertilization.

In this study, we compared the results of intracytoplasmic sperm injection (ICSI) in patients with normal semen parameters and a history of failed fertilization with conventional IVF (study group) and in patients with male factor infertility (control group). Patient and cycle characteristics were similar in both groups. The mean number of retrieved and metaphase II oocytes, fertilized oocytes, embryos developed, embryos transferred and the number of cycles with fertilization failure also did not differ between groups. Although differences were not statistically significant, pregnancy rate (56.3% vs. 31.5%), implantation rate (14.2% vs. 12%) and ongoing pregnancy rate (37.5% vs. 17.7%) per embryo transfer were higher in the study group than the ones in the control group. We concluded that previous idiopathic fertilization failure with conventional IVF is not associated with poor outcome in subsequent ICSI treatment.