Transfer Direct System as a New Method for Embryo Transfer

Inclusion Criteria: 1. Patients whose written informed consent is obtained, approved by the Ethics Committees for Investigation with Medicinal Products (ECRmp) after being duly informed of the nature of their disease and after voluntarily accepting the treatment program, knowing the potential risks, benefits, and inconveniences. 2. Patients who are going to undergo ART with a SET and have at least one vitrified euploid blastocyst with PGT-A (Preimplantation Genetic Test for the detection of Aneuploidy). 3. Women of reproductive age between 18 and 50 years (both inclusive) 4. Body mass index (BMI): \<30 kg/m2 5. Absence of adenomyosis and endometriosis 6. Uterus without pathologies that can contraindicate the transfer or may hinder implantation (e.g., polyps, fibroids that come into contact with the cavity, or Asherman syndrome) or without a history of thin endometrium or irregular patterns in thin endometrial preparations. 7. Absence of immune pathologies (e.g., lupus) that could endanger the health of the patient. 8. Easy transfer test or history of embryo transfer without difficulty or factors that indicate that the transfer is easy. Exclusion Criteria: 1. Difficult or very painful transfer tests. 2. Pathologies of an oncological nature. 3. The existence of serious or uncontrolled bacterial, fungal, or viral infections that, in the opinion of the principal investigator, may interfere with the patient's participation in the study or the evaluation of its results. 4. Other circumstances or difficulties that, in the opinion of the investigator, may pose a risk to the subject or reduce the chances of obtaining satisfactory data to achieve the objectives of the study, such as a history of severe preeclampsia without assessment by the obstetric team, psychiatric pathologies without prior assessment by the psychiatrist, uncontrolled or destabilized cardiac pathologies.