Successful pregnancy after oocyte activation by a calcium ionophore for a patient with recurrent intracytoplasmic sperm injection failure, with an assessment of oocyte activation and sperm centrosomal function using bovine eggs

Objective To report a successful pregnancy after intracytoplasmic sperm injection (ICSI) with artificial oocyte activation (AOA) on a patient whose fertilization rate after ICSI was extremely low; and to report on cytologic analyses of the fertilization failure (FF) eggs after ICSI and a biologic assessment of the sperm of this patient. Design Case report with an assessment of gamete function. Setting University hospital and an experimental laboratory. Patient(s) A couple with severe oligoasthenozoospermia, whose seventh attempt at ICSI ended in the failure. Intervention(s) Cytologic analyses of FF eggs after ICSI, AOA after ICSI, and analyses of human sperm oocyte activation ability and centrosomal function. Result(s) Fertilization arrest after ICSI was observed in FF eggs at various stages of fertilization. After artificial oocyte activation by exposure to ionomycin, clinical pregnancy was confirmed, and a healthy baby was born. As assessed by heterologous ICSI of human sperm into bovine oocytes, there was no significant difference in the oocyte activation rates between the patient's and control sperm, but the sperm centrosomal function was low in the patient's sperm (48.5% vs. 69.6%). Conclusion(s) We report a successful pregnancy after ICSI with AOA using a calcium ionophore, after critical cytologic analyses of the FF eggs. Furthermore, sperm centrosomal function was low, indicating that sperm's ability to process the events of fertilization after the oocyte activation was poor in this patient.