The purpose of this study is to analyze AMH levels in patients with prolonged FHA (more than 2 years). Based on previous studies, we can assume that prolonged FHA may mimic a condition of primary hypogonadotropic hypogonadism, due to a lasting interruption of gonadotropin release. Furthermore, after the resumption of the spontaneous menstrual cycle, we will reanalyze AMH levels, which we hypothesize to find higher. If our hypotheses are confirmed correct, we could support the thesis that AMH is not a good index of ovarian reserve in patients with functional hypothalamic amenorrhea.

Inclusion Criteria:

• Women aged 15-34 years.
• Diagnosis of functional hypothalamic amenorrhea (for at least 2 years).
• Signature of informed consent.

Exclusion Criteria:

• Polycystic ovary syndrome
• Taking oral contraceptives in the previous three months
• Other clinically relevant endocrinopathies
• positive MAP-test (Medroxyprogesterone acetate test)
• Estroprogestin replacement therapy
• Autoimmune disorders
• Failure to sign informed consent

Patients with functional hypotalamic amenorrhea (FHA) will be recruited from the DH of Dysfunctional Gynecology (UOSD Diagnostic and Medical Therapy of Menstrual Dysfunction and Marital Infertility) Department of Women's, Children's and Public Health Sciences of the A. Gemelli IRCCS University Polyclinic Foundation. Possible enrollment in the study protocol will not affect or alter in any way the patient's clinical course or adherence to good clinical practice guidelines. A group of healthy controls will also be enrolled, respecting the same exclusion criteria, from among the patients afferent to the Day Hospital of Dysfunctional Gynecology (healthy control is defined as: patient not suffering from functional hypothalamic amenorrhea, not from polycystic ovary syndrome and with 10-12 menstrual cycles per year).