Umbilical Cord Plasma for Treating Endometrial Pathologies (Thin Endometrium / Asherman's Syndrome/ Endometria Atrophy)

UMBILICAL CORD DONORS Donors of umbilical cord blood will be women (and their partners, if applicable) who give birth to a live newborn(s) in the Gynecology and Obstetrics service of HUP La Fe; the same umbilical cord collection criteria will be followed as standardized in HUP La Fe for the donation of this biological product. GROUP A Inclusion Criteria: * Patient information sheet and signed informed consent. * Female, acting voluntarily, aged between 18 and 48 years at the time of recruitment. * BMI ≥ 18 kg/m2 and ≤ 35 kg/m2. * Patients with premature ovarian failure (amenorrhea prior to 40 years of age and FSH \> 40 IU/L). Exclusion Criteria: * Active genital infection proven at the time of recruitment; chronic endometritis. * Known endometrial pathology. * Psychological disorder that may hinder study follow-up. * Positive results after viral safety analysis (HBsAg, HBcAb, HCV, HIV1, HIV2, syphilis). * Presenting any syndrome or condition that, from the principal investigator's point of view, could pose a risk to the study or to the patient. * Any significant clinical anomaly detected during the recruitment process; simultaneous participation in another clinical study that could affect the objectives of the present study or previous participation in this same study. GROUP B Inclusion Criteria: * Information and signed informed consent. * female, acting voluntarily, aged between 18 and 48 years at the time of recruitment. * body mass index (BMI): ≥ 18 kg/m2 and ≤ 35 kg/m2. * Patients undergoing an assisted reproduction cycle. * Endometrial thickness \< 5mm despite estrogen administration for more than 10 days and/or evidence of Asherman's Syndrome. Exclusion Criteria: * Active genital infection proven at the time of recruitment; chronic endometritis. * Known endometrial pathology. * Psychological disorder that may hinder study follow-up. * Positive results after viral safety analysis (HBsAg, HBcAb, HCV, HIV1, HIV2, syphilis). * Presenting any syndrome or condition that, from the principal investigator's point of view, could pose a risk to the study or to the patient. * Any significant clinical anomaly detected during the recruitment process; simultaneous participation in another clinical study that could affect the objectives of the present study or previous participation in this same study.