Could Artificial Oocyte Electro -Activation Timing Affect the Fertilization Rate in Post-Intracytoplasmic Sperm Injection (ICSI)?

Abstract Background: Intracytoplasmic Sperm Injection (ICSI) related fertilization failure has been of utmost importance in research since the technique was discovered. The search for the root cause, including that of male factor infertility, has been investigated heavily in the past decade. One of the efforts made to solve this issue was the introduction of artificial oocyte activation (AOA) which was designed to combat this unfortunate outcome. Aim of Study: To review the electroactivation technique for artificial oocyte activation and the impact of its different timing on ICSI in severe male factor cases. Study Design: This study is a prospective randomized control study. Setting: The Egyptian IVF-ET center (a private IVF center in Egypt) in cooperation with the Genetic Engineering and Biotechnology Research Institute, University of Sadat City. Patients: Seventy-six participants were chosen for the study, all of them had either severe oligoteratoasthenospermia, non-obstructive azoospermia with complete teratospermia, or fully immotile spermatozoa. Patients who had total or limited fertilization post ICSI procedure were also included. Intervention: After the pick-up procedure, the collected oocytes (n=862) from 76 patients were randomly divided after ICSI into two groups: The study group A (n=408) was subjected to electroactivation, and the control group B (n=454) with no electroactivation. The cases included in the study group were divided into two groups: Group (I) includes cases that were electroactivated within 30 minutes after ICSI (n=34) while group (II) included cases that were electroactivated in 2 hours after ICSI (n=42). Main Outcome Measures: Fertilization and degeneration rate.
Results: Seventy-six ICSI cycles were included in the study. Electro activated group had a considerably greater fertilization rate than the control group (63% vs. 41%). The oocyte degeneration rate was not statistically significant between the two groups (1% vs 0%). On the other hand, the fertilization rate was statistically significantly higher in group (II) as compared with group (I) (70% vs 52%). Non-significant difference was observed between the two groups regarding the oocyte degeneration rate (0.5% vs 0.4%). Although limited fertilization resulted in 17 cycles in the control group and 6 cycles in the study group, total fertilization failure (TFF) appeared in only 3 cycles and embryo transfer were cancelled. Conclusion: Some selected patients with limited fertili-zation potential may benefit from artificial oocyte activation (AOA) employing an electroactivation approach. Performing electroactivation in 2 hours after ICSI resulted in a significantly higher fertilization rate compared to direct or within 30 minutes electroactivated cases, such result if applied may lead to a better fertilization outcome in lab practice.