TRAP Study: Testosterone for Androgen Receptor Polymorphism

Inclusion Criteria: * Patients with low ovarian reserve according to Bologna criteria: at least two of the following three: 1. Age equal to or greater than 40 years. 2. Previous cycle with less than 4 oocytes retrieved. 3. Low ovarian reserve markers (antral follicle count \<5-7; AMH \<0.5-1.1 ng). * Carriers of androgen receptor polymorphism: between 22 and 24 CAG repeats. * Body Mass Index (BMI) less than 32. * Indication for in vitro fertilization. * Presence of both ovaries. * Absence of ovarian cysts. * Absence of endometriosis. * Normal karyotype and fragile X study. * Absence of severe male factor. * Semen sample from ejaculate. * Ability to comply with the study protocol. * To have given written consent. Exclusion Criteria: * Non-compliance with instructions or non-formalization of informed consent. * Concurrent participation in another study.