RESUMEN
OBJECTIVE: To assess the Ca2+-releasing ability of sperm involved in partial hydatidiform moles. DESIGN: Analysis of the activating and Ca2+-releasing ability of human sperm. SETTING: University hospital research laboratory. PATIENT(S): Patients undergoing intracytoplasmic sperm injection (ICSI) treatment. INTERVENTION(S): Microinjection of mouse and human oocytes with sperm. MAIN OUTCOME MEASURE(S): Measurement of the fertilizing and Ca2+-releasing ability of human sperm. RESULT(S): The mouse oocyte Ca2+ analysis showed that only 19.0% (4/21) of the mouse oocytes injected with sperm involved in molar pregnancies exhibited a normal pattern of Ca2+ oscillations versus 63.2% (36/57) of those injected with control sperm. Further, 83.3% (15/18) of donated in vitro-matured human oocytes injected with deficient sperm did not exhibit any Ca2+ release, while 76.9% (10/13) failed to show normal pronuclear development. Yet the sperm oocyte activation factor phospholipase C zeta (PLCζ) was present in the majority (96.6%, n=113) of the analyzed sperm at a normal expression level. Eventually, fertilization failure was overcome with assisted oocyte activation in subsequent therapeutic ICSI cycles, which led to normal deliveries. CONCLUSION(S): Sperm that previously provoked recurrent partial hydatidiform mole pregnancies due to dispermic fertilization is not able to activate human oocytes or trigger the normal pattern of Ca2+ oscillations in mouse and human oocytes in vitro.