Activation effect of calcium ionophore A23817 on the oocyte after failure of intracytoplasmic sperm injection fertilization

Abstract

Objective To explore the effect of calcium (Ca2+) ionophore A23817 on the oocyte after intracytoplasmic sperm injection (ICSI) fertilization failure. Methods A total of 53 cycles conducted oocyte activation with Ca2+ ionophore A23817 in the second ICSI treatment, due to low fertilization and total fertilization failure in the first ICSI cycles, from January 2016 to January 2018 in reproductive center of the First Affiliated Hospital of Zhengzhou University, were included in this retrospective research. According to the sperm quality, patients were divided into four groups, including group A (severe oligoasthenospermia and obstructive azoospermia), group B (globozoospermia), group C (other types of sperm deformity), group D (other factors). According to self-control study, oocytes in the second oocyte activation cycles were set as assisted oocyte activation (AOA) subgroup, and the oocytes in their first cycles conducted normal ICSI treatment were set as control subgorup. Laboratory indexes and pregnancy outcomes were compared between AOA subgroup and control subgroup, and the activation rate in AOA subgroup was compared among different experimental groups. Results 1) The 2 pronucleurs (PN) rate in AOA subgroup of groups A, B and C (36.9%, 66.7%, 58.2%) was statistical significantly higher than control subgroup in groups of A, B and C (12.7%, 0.0%, 17.6%; all P was 0.00), which was not significantly different in group D (P>0.05). 2) The implantation rate in AOA subgroup (56.5%) was statistically higher than that in control group (0.0%) in group C (P=0.02), which was not significantly different in groups A and D. In AOA subgroup of group B, some embryos were successfully implanted after transfer, whereas no embryos can be transferred in control subgroup. 3) There were significant differences of activation rate among groups A, B and C, and that of group B (86.7%) was the highest among them. Conclusion To the patients with repeated fertilization failure due to severe sperm factors, Ca2+ activation can significantly improve the fertilization of ICSI, besides, Ca2+ activation can also significantly improve the pregnancy outcomes of ICSI for the patients with sperm deformity. Key words: Activation by calcium ionophore; Intracytoplasmic sperm injection (ICSI); Fertilization failure; Sperm deformity