BackgroundSecond ejaculation can influence sperm quality which may define the first-line treatment. The purpose of this study was to evaluate the effectiveness of a second ejaculation in decreasing the unexpected intracytoplasmic sperm injection (ICSI) rate by a propensity score-matched (PSM) analysis.MethodsPatients who were projected to undergo IVF were included between January 2016 and November 2021 in this monocentric, retrospective analysis. 2782 patients included in the study, 143 and 2639 patients were non-randomized in the unexpected ICSI and IVF groups, respectively. One hundred fourteen patients with unexpected ICSI produced two semen samples on the day of ovum pick-up. After 1:4 PSM, we matched 61 patients in the second ejaculation IVF group to 238 patients in the conventional IVF group. Outcomes of sperm quality, fertilization rate, embryo quality, and pregnancy were compared.ResultsSecond ejaculation significantly improved sperm concentration, progressive motility before and after sperm swim-up, total progressive motility sperm count after swim-up, and decreased sperm DNA fragmentation (SDF). Sixty-one of 114 (53.5%) unexpected ICSI couples had enough total progressive motility sperm for IVF with the second ejaculation. There were no differences in basic clinical characteristics between couples in second ejaculation IVF and matched-conventional IVF group. For the two groups, no differences were observed in IVF outcomes. However, a significant increase in good-quality blastocyst rate was observed for second-ejaculation IVF couples. Univariate and multivariate linear regression analysis also confirmed that the second ejaculation was an independent risk factor for the good quality blastocyst rate.ConclusionSecond ejaculation could be an economical and secure alternative to get good quality sperm, and blastocyst and decrease the rate of unexpected ICSI. Multicenter studies should be conducted to confirm the potential advantages of using second ejaculation IVF in effectively reducing the rate of ICSI.