Adult-onset amenorrhea: a study of 262 patients.

A series of 262 patients with amenorrhea of adult onset are reported. Hypothalamic suppression followed by inappropriate positive feedback, and then hyperprolactinemia and ovarian failure are the most frequently encountered etiologies. Other etiologies are diverse and numerically less frequent. Amenorrhea after use of oral contraceptives, or postpill amenorrhea, occurred in 77 (29%) of all patients. The average age of presentation, prior menstrual history, associated morbidity, and subsequent reproductive potential of each diagnostic group are reported. Adult-onset amenorrhea has a less significant impact on future wellbeing than was reported for a similar-sized group of patients whose amenorrhea developed as a result of pubertal aberrancy.