Recombinant LH Prior to Ovarian Stimulation in Poor Ovarian Responders (PRE-LH)

Inclusion Criteria: 1. -Patients with POR according to specific criteria that are in line with the criteria defined by the ESHRE (Bologna Criteria), according to which a patient is classified as a poor ovarian responder when she meets two of the three of the following criteria: I.- Previous episode of POR (≤3 oocytes) with conventional stimulation protocol II.- Abnormal ovarian reserve test with an antral follicle count (AFC) \<5-7 and/or anti-mullerian hormone values (AMH) \<0.5-1.1 ng/mL. III.- Women ≥40 years old and/or who have any other risk factor for POR. In addition, two episodes of POR after maximal stimulation are sufficient to define a patient as poor responder in the absence of advanced maternal age or abnormal ovarian reserve test. 2. \- Women ≥35 to ≤43 years for COS and assisted reproduction techniques (ART). 3. \- Couple or single woman, accepting preimplantation genetic diagnosis (PGS) after blastocyst biopsy and delayed transfer for selection of euploid embryos. 4. \- Body Mass Index (BMI) between18 and 30 kg/m 2 , inclusive. 5. \- Ejaculatory sperm with concentration ≥ 5 mill spermatozoa/mL and ≥ 5 mill total spermatozoa progressive motility. Bank and cryopreserved semen allowed. 6. \- Informed consent completed, signed and dated. Exclusion Criteria: 1. \- Cases of recurrent spontaneous miscarriage (≥2 clinical miscarriages) or implantation failure (after transfer of 6 good D3 embryos or 4 good blastocysts) will be excluded. 2. \- Use of testicular or epididymal spermatozoa as well as ejaculate with concentration \< 5 mill spermatozoa/mL and \< 5 mill total spermatozoa progressive motility. 3. \- Primary ovarian failure, PCOS (in accordance with the Rotterdam criteria) or ovary/s inaccessible for oocyte retrieval. 4. \- Anatomical uterine abnormalities and any endometrium or myometrium pathology (adenomyosis, polyps, myoma, etc.) that may interfere with implantation or pregnancy. Patients with previous polypectomy, myomectomy or surgery for septate/subseptate/arcuatus uterus should not be excluded. 5. \- Presence of unilateral or bilateral hydrosalpinx that has not been surgically removed or ligated. 6. \- Presence of level III-IV endometriosis. 7. \- History of tumours in the hypothalamus or pituitary gland, or ovarian, uterine or breast cancer. 8. \- Abnormal bleeding of undetermined origin. 9. \- Known infection with human immunodeficiency virus, active hepatitis B or C virus in the woman or her partner. 10. \- Known allergy or hypersensitivity to the drugs administered during the trial. 11. \- Concurrent significant medical pathologies that would endanger the patient's safety (uncontrolled thyroid or adrenal dysfunction, severe hepatic or renal impairment, etc.) or interfere with the test evaluations or the clinical outcomes (i.e. confirmed thrombophilia). 12. \- Use of concomitant medication or any other circumstances that, in the opinion of the investigator, interferes with the development of the trial or does not ensure the safety and efficacy of the data. 13. \- Simultaneous participation in another clinical trial or previous participation in this study. 14. \- Participation in another clinical study two months before inclusion in the present study that could affect its objectives.