Causes of Primary Amenorrhea - Differential Diagnosis Algorithm No onset of menarche by age 16 with secondary sexual characteristics OR No onset of menarche by age 14 without secondary sexual characteristics Ovarian Etiology - High FSH, Low Estrogen: • 46, XX Gonadal Dysgenesis (e.g. Fragile X, Balanced Translocations, Turner's mosaic) • 46, XY Gonadal Dysgenesis (e.g. Swyer's Syndrome) • 45, XO Turner syndrome • Savage syndrome (ovarian resistance) • Premature Ovarian Failure (Autoimmune, Iatrogenic) Receptor Abnormalities and Enzyme Deficiencies: • Androgen insensitivity • 5-a Reductase deficiency • 17- a Hydroxylase deficiency • Vanishing Testes Syndrome • Absent Testes Determining Factor Congenital Outflow Tract Anomalies: • Imperforate hymen • Transverse vaginal septum • Vaginal agenesis (Mayer-Rokitansky-Küster-Hauser syndrome) • Cervical stenosis Central - Hypothalamic: • Functional (e.g. eating disorder, weight loss, stress, excessive exercise, illness) • Congenital GnRH deficiency (Kallmann syndrome) • Constitutional delay of puberty Central - Pituitary: • Surgery • Irradiation • Tumor, Infiltration • Hyperprolactinemia • Hypothyroidism #Primary #Amenorrhea #Differential #Diagnosis #Algorithm #Causes #OBGyn #Gynecology
