Clinical Research Directory

Inclusion Criteria: * First IVF cycle patients * Patients who sign the informed consent form * Patients between 18 and 37 years old. * Patients BMI ≤ 30 * Patients who have frozen blastocysts of good quality (grade A or B) * Patients with negative vaginal and endocervical cultures * Patients with an antimullerian hormone level greater than 1 ng/mL. * IVF patients with an endometrial thickness greater than 7mm with trilaminar pattern on the day of the pre-progesterone visit. * And who meets one of these conditions: 1. Not having had a previous embryo transfer. 2. Have failed only one embryo transfer Exclusion Criteria: * Patients with seminal data of the couple with severe oligozoospermia (sperm concentration \<1 million sperm per ml) or azoospermia (absence of sperm in the ejaculate) * Patients diagnosed with at least one of the following uterine pathologies: endometriosis, cancer, malformations, untreated polyps, or submucous fibroids. * Patients diagnosed with at least one of the following medical pathologies: Polycystic ovary syndrome (PCOS), insulin-dependent diabetes mellitus, Cushing's syndrome, uncorrected thyroid dysfunction, hepatic and/or renal insufficiency, a pathology that contraindicates ovarian stimulation and/or gestation, antiphospholipid syndrome, and autoimmune disease. * Patients who are currently taking any medication other than contraceptive treatments, which may interfere with fertility or menstrual cycle regulation. * Evidence of drug, tobacco, or alcohol abuse or dependence according to medical history or information provided by the patient. * Inadequate understanding (oral and written) of the Spanish language.