Clinical Research Directory

Acrosome Reaction Induction Prior to ICSI

Introduction To get through the egg vestment and fertilize the oocyte, the spermatozoon uses its acrosomal enzymes. When Intracytoplasmic sperm microinjection (ICSI) is performed, the acrosomal enzymes are introduced with the spermatozoa inside the ooplasme. The fate of these enzymes, that normally never enter the oocyte, is not known. But they impair the embryo development. Indeed, although the ICSI outcome is satisfactory in humans, a series of studies in many species (mouse, hamster, cattle, and horse) demonstrate the deleterious effects of the introduction of acrosomal material in the oocyte cytoplasm, on embryo and fetal development. These studies have also shown two things: * The bigger the acrosome, the more deleterious are the effects of their introduction into the egg. * And that the induction of the acrosome reaction (AR) prior to ICSI significantly improves embryonic development and the number of babies born after embryo transfer as it is the case in the mouse. The microinjection of acrosome reacted sperm increases from 40 to 70 % the percentage of pups born per embryo transferred. Hypothesis : It is possible to improve ICSI outcome, in terms of babies born in human, by induction of the AR prior to microinjection. After studying several techniques, we choose a physiologic technique for acrosome induction. The induction of acrosome reaction prior to ICSI should improve in utero fetal development and decrease the rate of miscarriage and pregnancy arrest.