Pubertal Development and Disturbances of Menarche

Abstract

Puberty progresses sequentially until adult sexual characteristics are attained (Tanner, 1969; Marshall and Tanner, 1969; Root, 1973). Because there are variations in the age at which adolescence begins, the physiologic and endocrinologic progression relates more closely to the physical stages of sexual maturation. The stages of pubertal development in the female patient have been described in detail (Tanner, 1969) and are summarized in figure 5.1 in which the sequence of breast development, pubic hair growth, menarche, and skeletal growth is depicted. Because various workers have employed somewhat different criteria for description of this progression, a comparative classification is also presented in table 5.1. Ethnic and geographic considerations affect the times of appearance of sexual characteristics, but in girls in the United States, the following landmarks are recognized. The initiation of breast development is at age 10.8 yr, the appearance of pubic hair starts at about 11 yr, the onset of menstruation is between ages 12.6–12.9 yr, and the peak height velocity is achieved at around age 12 yr. A relationship has been demonstrated between body weight and time of puberty, and, in American girls, the critical weight at which adolescent maturation begins is 47.8 kg (and the height is 155 cm). This relationship may well explain the early onset of puberty in obese girls, and delayed menarche found in starving girls. The pubertal growth spurt is accompanied by changes in several physical parameters, including an increase in muscle size and numbers of cells, energy requirements, metabolic rate, carbohydrate tolerance, and water and electrolyte balance.