Causes of Primary and Secondary Amenorrhea - Differential Diagnosis Algorithm Primary Amenorrhea - 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 • Receptor Abnormalities and Enzyme Deficiencies • Congenital Outflow Tract Anomalies • Central - Hypothalamic • Central - Pituitary Secondary Amenorrhea - Absence of menses for more than 3 cycles or 6 months in women who were previously menstruating • Ovarian - Normal FSH • Ovarian - High FSH • Hypothalamic - Negative progesterone challenge, Low FSH, Low estrogen: • Pituitary - High Prolactin • Pituitary - Other • Outflow Tract Obstruction #Primary #Secondary #Amenorrhea #Differential #Diagnosis #Algorithm #Causes #OBGyn #Gynecology
