Effect of Timing of Oocyte Denudation Before ICSI in an Oocyte Donation Model

Inclusion Criteria: * Oocytes retrieved from healthy donors, younger than 32 years old , with proven maternity(preference), who meet the admission criteria of ovodonation program: * The oocytes included will be the product of antagonist stimulation protocol and with Gnrh agonists trigger. (see annex) * Healthy women under 50 years of age , who meet the criteria as receptors into the ovodonation program. * Oocytes retrieved after 36.5 h + -1 h of administration of triptorelin acetate. * Only mature oocytes, in stage MII, will be included and injected. * Use of fresh or thawed semen for the ICSI. Exclusion Criteria: * Cases of severe male factor such as azoospermia or severe oligo-astheno-teratospermia( alone or combinated) * Sperm samples from surgical procedures (biopsy / testicular or epididymal puncture) * Donors with a polycystic ovarian profile, according to The Androgen Excess and PCOS Society (AES), 2006. * Thawed donated oocytes * Oocytes from patients who have previously donated within a period of less than three months. * Donors whith poor response (oocyte retrieved less than \< 4 oocytes). * Suspicion or signs of Endometriosis in donor patient.