TY - CHAP M1 - Book, Section TI - Primary Amenorrhea A1 - Fitzgerald, Paul A. A2 - Papadakis, Maxine A. A2 - McPhee, Stephen J. A2 - Rabow, Michael W. Y1 - 2021 N1 - T2 - Current Medical Diagnosis & Treatment 2021 AB - Menarche ordinarily occurs between ages 11 and 15 years (average in the United States: 12.7 years) (see also Chapter 18). The failure of any menses to appear is termed “primary amenorrhea,” and evaluation is commenced (1) at age 14 years if neither menarche nor any breast development has occurred or if height is in the lowest 3%, or (2) at age 16 years if menarche has not occurred. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2023/06/04 UR - accessmedicine.mhmedical.com/content.aspx?aid=1175787055 ER -