L26/P-256 Gamete activation technology improves clinical and embryological outcomes in patients with repeated ART failures caused by male factors

Abstract Study question If gamete activation technology improves pregnancy outcomes. Summary answer Gamete activation technology improves clinical and embryological outcomes in patients with repeated ART failures caused by male factors. What is known already Males factors affect approximately 50% of patients of infertility. The implementation of intracytoplasmic sperm injection (ICSI) technology enables patients afflicted with severe asthenospermia, teratospermia, and nonobstructive azoospermia to birth biological offspring. In clinical practice, certain infertile couples, such as who suffer from severe sperm structural defects or sperm maturation disorders, still frequently encounter unfavorable clinical outcomes, such as fertilization failure, compromised embryo quality, and abortion, which are collectively termed repeated assisted reproductive technology (ART) failures. Therefore, more precise methods or technologies are needed to improve the clinical outcomes of these patients. Study design, size, duration This retrospective cohort study included patients who had experienced at least two controlled ovarian hyperstimulation (COH) transplant cycles from August 2021 to March 2025. After inclusion and exclusion criteria, a total of 224 patients were ultimately included. Participants/materials, setting, methods The study group included 85 patients receiving sperm activation, 79 patients receiving oocyte activation, 60 patients receiving both sperm and oocyte activation (gamete coactivation). The data of control group derived from the first ART cycle with fresh embryo transfer without gamete activation of patients. The baseline and cycle characteristics and reproductive outcomes were compared between the two groups. Main results and the role of chance Among all patients in the activation group, the fertilization rate (45.32% vs 27.68%, P < 0.01), clinical pregnancy rate (31.25% vs 5.36%, P < 0.01), and live birth rate (24.06% vs. 0%, P < 0.01) were all significantly higher than in the initial ICSI cycle. In every activation group, there was a significant improvement in IVF-lab parameters and clinical outcomes after taking different activation measures. Among the three groups, the sperm activation group has the highest median fertilization rate(73.81% vs. 54.88% vs. 52.43%), high-quality embryo rate(42.96% vs. 39.00% vs. 39.08%), clinical pregnancy rate(36.47% vs. 29.11% vs. 26.67%), and live birth rate(32.94% vs. 18.98% vs. 16.67%). There was no significant difference in the above parameters between the oocyte activation group and the gamete co-action group. As for the safety of gamete activation, compared with patients undergoing ICSI during the same period, the activation group showed no significant difference in rates of malformed fetuses (P = 0.36) or neonatal mortality (P = 0.36). Limitations, reasons for caution As this was a single-center study conducted over five years, the sample size was relatively small. In addition, our study was only followed up to the perinatal period and neonatal birth. The evaluation of genetic and epigenetic integrity are still needed. Wider implications of the findings Our study provide guidance for the clinical application of gamete activation. Trial registration number No