Clinical efficiency of a ready-to-use medium for human embryo culture supplemented with growth factors in patients with previous in vitro fertilization failures

INTERVENTION: Participants are randomly allocated to one of two groups. Group 1: Participants receive intracytoplasmic sperm injection (ICSI) treatments carried out using ISM1 for embryo culture and transfer. Group 2: Participants receive intracytoplasmic sperm injection (ICSI) treatments carried out using Embryogen for embryo culture and transfer. For both groups, participants undergo controlled ovarian stimulation between day 12 and 20 of their menstrual cycle using gonadotropin‐releasing hormone analogs in combination with a graded gonadotropin administration. Oocyte retrieval is performed 35 hours after ovulation induction with either 5,000 or 10,000 IU of human chorionic gonadotropin (hCG). High quality oocytes (colourless and of regular shape, with regular zona pellucida and small perivitelline space without debris, homogeneous cytoplasm and no vacuoles or granulations) are cultured at 37°C in an atmosphere of 6% CO2, in either the ISM1 or Embryogen medium. Insemination by ICSI of the best available MII oocytes, in accordance with the Italian law regulating Assisted Reproductive Technology, is then used between 2 and 3 days after donation. The follow up will be completed at confirmation of clinical pregnancy by ultrasound check of gestational chamber, 30 days after the embryo transfer. CONDITION: Intracytoplasmic sperm injection (ICSI) and embryo culture ; Pregnancy and Childbirth ; Intracytoplasmic sperm injection (ICSI) and embryo culture PRIMARY OUTCOME: Implantation rate (defined as the number of implanted embryos per number of transferred embryos) is measured 30 days after embryo transfer. SECONDARY OUTCOME: Pregnancy rate (defined as the number of pregnancies per number of transferred embryos) is measured using ultrasound of gestational chamber 30 days after embryo transfer. INCLUSION CRITERIA: 1. Female patients with at least one previous unsuccessful IVF attempt, in which a clinical pregnancy was not established (including biochemical pregnancies or miscarriages) 2. Aged between 25 and 45