Menstrual Disorders in the Adolescent: Amenorrhea
Margaret M. Polaneczky MD1
Gail B. Slap MD2
1 Assistant Professor of Obstetrics-Gynecology, University of Pennsylvania School of Medicine
2 Associate Professor of Medicine and Pediatrics, University of Pennsylvania School of Medicine, and Director, Craig-Dalsimer Program in Adolescent Medicine, Hospital of the University of Pennsylvania, Children's Hospital of Philadelphia
The menstrual history is an integral part of the evaluation of the adolescent femaie. Abnormal menstrual flow or timing may be the first sign of systemic illness or sexually transmitted disease. Amenorrhea may signal an endocrine or genetic disorder or may suggest structural abnormalities of the genital tract. Most importantly, any abnormality in menstruation should alert the clinician to the possibility of pregnancy.
Normal Menstrual Cycle
The average age of menarche in the United States is 12.8 years and ranges from 9 to 16 years. Menarche usually occurs 2 to 2.5 years after breast budding and 1 year after the growth spurt. Consequently, the absence of menarche at 15 years of age may be normal in an adolescent who just passed her growth spurt but abnormal in an adolescent who completed puberty 2 years earlier. Most early menstrual cycles are anovulatory. As a result, menses in the young adolescent often are irregular and may be prolonged or heavy. Dysmenorrhea and premenstrual symptoms tend to accompany ovulatory cycles and, therefore, are more common in the older adolescent.
Regular ovulatory cycles usually are established within 1 to 2 years of menarche. Although normal cycle length ranges from 21 to 45 days, the length for a given individual is fairly constant.
