Artificial oocyte activation in ICSI cycles in severe male infertility cases: is calcium ionophore or piezoelectric better?

To compare the effectiveness of calcium ionophore–induced artificial oocyte activation (AOA) and piezoelectric stimulation in improving fertilization, embryo quality, and pregnancy outcomes in ICSI cycles of severe male factor infertility. A prospective controlled study was conducted at the Istanbul University IVF Center between December 2023 and June 2025. Data collection and follow-up for all pregnancy outcomes, including live birth, were completed before July 2025. The study included 150 couples with severe male factor infertility divided into three groups: (i) Control (conventional ICSI, n = 50), (ii) ICSI + Calcium ionophore (n = 50), and (iii) ICSI + Piezoelectric (n = 50). Severe male factor infertility was defined according to WHO (2021) criteria. Oocytes were fertilized and cultured under standardized conditions. Embryo morphology was assessed on Day 3 according to the Istanbul Consensus (2011) criteria and on Day 5 using the Gardner and Schoolcraft grading system. Statistical comparisons were performed using ANOVA, Kruskal–Wallis, and chi-square tests, with p < 0.05 considered significant. The primary outcome measure was the fertilization rate, while embryo quality and clinical outcomes were evaluated as secondary outcomes. Fertilization rates were significantly higher in the ICSI+Piezoelectric group compared with both the control and ICSI+Calcıum ionophore groups (p < 0.0001). The proportion of good-quality (Grade I) embryos was also greater in the ICSI+Piezoelectric group (38.2%) than in the control (28.3%) and ICSI+Calcıum ionophore (29.5%) groups (p < 0.05). No statistically significant differences were observed in pregnancy outcomes, including implantation, clinical pregnancy, ongoing pregnancy, or live birth rates; however, a non-significant trend toward higher ongoing pregnancy rates was noted in the ICSI+Calcıum ionophore group. Piezoelectric activation was associated with higher fertilization rates and improved early embryo morphology; however, these improvements did not translate into statistically significant differences in clinical pregnancy or live birth outcomes.