Sperm involved in recurrent partial hydatidiform moles cannot induce the normal pattern of calcium oscillations

Abstract

To assess the Ca2+-releasing ability of sperm involved in partial hydatidiform moles. Analysis of the activating and Ca2+-releasing ability of human sperm. University hospital research laboratory. Patients undergoing intracytoplasmic sperm injection (ICSI) treatment. Microinjection of mouse and human oocytes with sperm. Measurement of the fertilizing and Ca2+-releasing ability of human sperm. 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. 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.