Aurora Test for ART Donor Patients (AURORA-Donor)

Inclusion Criteria Donor: * Patients are 18 to 35 years old * BMI between 17-30 * Regular menstrual cycles * AFC \> 8 * Patient profile in compliance with SEF (Sociedad Española de Fertilidad) directives for egg donation (medical, psychological and genetic screening, informed consent) * Patients' stimulation: GnRH Antagonist \& hr-FSH with GnRH Agonist trigger or Progesterone \& hr-FSH with GnRH Agonist trigger * Patients agree that the oocytes will be denuded for cumulus testing and provide written informed consent for participation to the study Exclusion Criteria Donor: * BMI \< 17 or \> 30 * Extreme irregular menstrual cycles (\<20 days or \>40 days) * AFC \< 8 * \<8 MII on previous egg retrieval * Women with history of poor oocyte maturation or known maturation defect or unexplained failure in previous treatments * Patients that fail to comply with SEF (Sociedad Española de Fertilidad) directives for egg donation (medical, psychological and genetic screening, informed consent) Inclusion Criteria Recipient: * Patients applying for ART egg donation with fresh/frozen sperm from the partner or frozen donor sperm. With eSB-FET in modified natural cycle or an HRT cycle. * Patients are from 18 to 50 years old. * Patients will be treated by ICSI (intracytoplasmic sperm injection) and eSB-FET (elective Single Blastocyst Frozen Embryo Transfer) * Recipient patients agree that the donors' oocytes will be denuded for cumulus testing and provide written informed consent for participation to the study Exclusion Criteria for oocyte Recipients * Patient included in any other prospective study. * BMI \< 17 or \> 35 * Severe uterine factor: Multiple myomectomy, multiple fibroids, major uterine malformation (unicorn, septum), Asherman Sd, severe adenomyosis * Repeated Implantation Failure or Repeated Pregnancy Loss after euploid Single Blastocyst Transfer * Severe male factor: Abnormal Caryotype or FISH, severe OAT / Cripto-Azoospermia, DNA Fragmentation \>50% after medical treatment * TESE / TESA (testicular sperm extraction/aspiration)