Embryo development and live birth in women with one previously failed full IVF/ICSI cycle

Purpose: To evaluate the embryological and pregnancy outcomes of women who failed in their first IVF treatment if they attempted a second cycle. Methods: For evaluating the embryological outcomes, the study cohort included 1,227 women who failed to obtain a live birth after the initial IVF cycle from September 2018 to August 2021 and returned for a second attempt. To evaluate reproductive outcomes including live birth rates (LBRs), 1227 women who returned for a second attempt were compared with 13,195 women undergoing their first oocyte retrieval with blastocyst culture attempted during the same study period. Results: In women who had a second cycle, the median number of oocyte retrieved (11 vs 9), fertilized oocytes (7 vs 5), usable embryos (6 vs 4) and blastocysts (3 vs 1) was higher in the second cycle compared to the first cycle (All p < 0.001). Blastocyst formation rates were significantly increased from 33% in the first cycle to 50% in the second cycle across the age group (p < 0.001). However, the primary transfer LBRs were significantly lower in the second cycle than that in the initial cycle (40.82% versus 51.79%, aOR: 0.74 [0.65, 0.84]). LBRs in the second cycle were 42.26%, 42.68%, 25.49% and 16.22% in women aged < 35, 35–37, 38–40, and > 40 years. Conclusion: There was a notable enhancement in laboratory outcomes following the second attempt in women whose initial IVF cycles were unsuccessful. However, the uncertainty inherent in the successful implantation and the consequent progression to live birth remains a significant challenge.