Switching to intracytoplasmic sperm injection provides no benefit in couples of poor embryonic development in the previous in vitro fertilization cycle.

This study aimed to evaluate the effectiveness of changing the insemination method in women who experienced poor embryonic development during the preceding cycle. A total of 15,886 conventional IVF in 9,311 women, performed between August 2015 and June 2023, were included in this study. Of these, 270 couples experienced IVF failure due to poor embryonic development in the first oocyte retrieval (OR) cycle, which was cancelled before transfer. The patients were stratified based on whether or not they switched to ICSI for subsequent attempts. Cumulative live birth rates (CLBRs) and a series of secondary outcomes were compared. The embryo utilization, high-quality embryo, blastocyst formation, implantation, cumulative clinical pregnancy, CLBR and miscarriage rates were comparable between the two groups, whereas the fertilization rate per oocyte retrieved was significantly lower in the ICSI group during the second OR cycle (60.76% vs. 70.42%, p < 0.001) and all OR cycles (60.02% vs. 71.69%, p < 0.001). Furthermore, the CLBRs in the ICSI and IVF groups after up to seven OR cycles were 41.35% and 36.84%, respectively. Most patients achieved live births during the second OR cycle (58.33%, ICSI vs. 62.86%, IVF). ICSI did not improve clinical or embryonic outcomes in women who experienced poor embryonic development in their preceding cycle.