I Pregnancy and postpartum A Intrauterine pregnancy B Ectopic pregnancy C Lactation II Iatrogenic A Medications (see Table 51.3 ) B Hormonal contraception III Endocrine A Hyperandrogenism Polycystic ovarian syndrome Congenital adrenal hyperplasia Adrenocorticoid tumor B Hypothalamic–pituitary axis disorders Caloric insufficiency a Chronic illness b Malabsorptive disorders c Strenuous exercise d Marked weight loss e Anorexia nervosa f Athletic triad Hyperprolactinemia a Medications (see Iatrogenic) b Pituitary tumor/other central nervous system tumors C Ovarian disorders Ovarian failure a Gonadal dysgenesis b Alkylating antineoplastic agents c Pelvic irradiation d Autoimmune disease Hormone-secreting tumors D Thyroid disorders Hypothyroidism Hyperthyroidism IV Miscellaneous