TY - CHAP M1 - Book, Section TI - Chapter 54. Amenorrhea A1 - Simon, Alex A1 - Chang, Wendy Y. A1 - DeCherney, Alan H. A2 - DeCherney, Alan H. A2 - Nathan, Lauren A2 - Laufer, Neri A2 - Roman, Ashley S. PY - 2013 T2 - CURRENT Diagnosis & Treatment: Obstetrics & Gynecology, 11e AB - Amenorrhea is literally defined as the absence of menses.Primary amenorrhea (seen in approximately 2.5% of the population) is clinically defined as the absence of menses by age 13 years in the absence of normal growth or secondary sexual development, or the absence of menses by age 15 years in the setting of normal growth and secondary sexual development.Traditionally, evaluation was usually initiated by age 16 years if normal growth and secondary sexual characteristics were present, and at age 14 years if absent.Because of secular trends toward earlier menarche over the past half century, the evaluation should begin at age 15 years, the age when more than 97% of girls should have experienced menarche.The decision to evaluate should be made with a full understanding of the patient's clinical presentation.Evaluation should not be delayed in the setting of neurologic symptoms (suggestive of hypothalamic–pituitary lesion) or pelvic pain (suggestive of outflow obstruction).Secondary amenorrhea is clinically defined as the absence of menses for more than 3 cycle intervals, or 6 consecutive months, in a previously menstruating woman.The incidence of secondary amenorrhea can be quite variable, from 3% in the general population to 100% under conditions of extreme physical or emotional stress.Table 54–1 lists the most common causes of secondary amenorrhea. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=56976305 ER -