The aim of this study is to demonstrate the efficacy of a single embryo transfer at blastocyst stage (Day 5) after co-culture on Autologous Endometrial Cell Culture (AECC) versus transfer of a single embryo at Day 3 after culture in conventional medium. Efficacy will be assessed in terms of clinical pregnancy rate 5 to 8 weeks after embryo transfer.

Inclusion Criteria:

• Women aged ≥ 18 and ≤ 36
• Undergoing ovarian stimulation for an In Vitro Fertilization (IVF) or Intra Cytoplasmic Sperm Injection (ICSI)
• Having experienced no more than 1 Embryo Transfer failure
• With basal FSH level ≤ 12 IU/l within the 6 months prior to the study
• Endometrial biopsy during the menstrual cycle preceding the ovarian stimulation (6 to 12 days after a documented ovulation)
• Negative serology for HIV 1 and 2, hepatitis B and C, HTLV 1 and 2, syphilis

Exclusion Criteria:

• Hypersensitivity to one of the culture media components
• Oocyte donation, sperm donation
• Thawed embryos transfer
• Women with endometriosis grade III and IV, chronic endometritis, hydrosalpinx, polycystic ovary, amenorrhoea, anovulation, uterus with malformation, uncontrolled prolactinaemia, uterine synechia, uterine fibroma, women exposed to distilbene, uterine polyps
• Women affected by pathologies associated with any contraindication of being pregnant
• Abnormal gynaecologic bleeding of undetermined origin
• Uncontrolled thyroid (TSH dosage) or adrenal dysfunction
• Neoplasias, any pathologies of the endometrium or the cervix