Successful fertilization and pregnancy after intracytoplasmic sperm injection and oocyte activation with calcium ionophore in a normozoospermic patient with extremely low fertilization rates in intracytoplasmic sperm injection cycles

Abstract Objective To investigate the effect of calcium ionophore on the fertilization rate of a patient with normozoospermia who nonetheless exhibited a low fertilization rate in intracytoplasmic sperm injection (ICSI). Design Case report. Setting In vitro fertilization center. Patient(s) A male patient whose sperm, though diagnosed as normal by semen analysis, exhibited a severely low fertilization rate in ICSI cycles. Intervention(s) Oocytes were activated by calcium ionophore after ICSI. Main outcome measure(s) Fertilization rate after oocyte activation; ultrastructure and protein expression of the patient's sperm. Result(s) The fertilization rate of oocytes activated with calcium ionophore (12 of 15, 80.0%) was higher than that of the nonactivated oocytes (4 of 16, 25.0%). Four embryos derived from the activated oocytes were transferred, resulting in a twin pregnancy. Further investigation revealed abnormalities in the patient's sperm: many nuclear vacuoles were observed and the expression of some proteins was absent. Conclusion(s) Oocyte activation with calcium ionophore was effective at increasing the fertilization rate of dysfunctional sperm characterized by ultrastructural and protein expression anomalies.