Amenorrhea

Throughout each stage of a woman's reproductive life cycle, from menarche to menopause, there may be variations in their menstrual cycle's length and amount secondary to many causes. This variation may be within the normal range or pathologic. Particularly during stages of the reproductive cycle (eg, menarche and perimenopause), when longer intervals between menstrual cycles commonly occur, clinicians may be unsure of the appropriate diagnostic studies or when an evaluation is indicated.

Amenorrhea is a menstrual symptom characterized by the absence of menstruation in a female of reproductive age. It can be classified as either primary or secondary amenorrhea. Primary amenorrhea is defined as having no history of menstruation by the age of 15 years or 3 years after thelarche; secondary amenorrhea is defined as the absence of menses for ≥3 months in a woman with previously regular menstrual cycles or ≥6 months in any woman with at least one previous spontaneous menstruation. Patients meeting the criteria for either primary or secondary amenorrhea warrant an evaluation. However, an evaluation for delayed puberty is indicated in adolescents aged 13 years with primary amenorrhea and no breast development.

There are numerous potential etiologies of amenorrhea. Most of the underlying causes of amenorrhea can be classified into general groups: outflow tract abnormalities, ovarian failure or insufficiency, hypothalamic or pituitary disorders, other endocrine gland disorders, and physiologic or medication-induced. When evaluating a patient with amenorrhea, a systematic approach should be used to consider each potential etiology. The initial work-up usually includes a comprehensive history and physical examination, a urine pregnancy test, serum hormone testing, and pelvic imaging. Additional testing may also be indicated based on the clinical presentation. Treatment depends on the underlying etiology and may include lifestyle interventions, hormone therapy or other medications, surgery, and mental health services.