Adolescent growth in height and its relation to menarche in contemporary American girls.

Abstract

Height measurements at frequent intervals, from age six to adulthood, of 338 middle-class American girls are used to examine contemporary height and height velocity at specified ages, the characteristics of the adolescent growth spurt and its relation to menarche. These data, analysed by fitting to a mathematical model (Preece and Baines 1978), are presented as tables of means and standard deviations, percentiles and correlations. There is no evidence of a trend towards increased or accelerated growth in height; in the United States and Western Europe, girls have been the same height at specified ages, and have grown at the same rate, for the past 45 years, at least. Examination of the data plots and the growth statistics of all 338 girls revealed a group of 67 girls (designated E) who are different from the remaining 271 girls (designated S). Plots of the E girls show no discernible growth spurt. Compared with the S girls, they are significantly taller at specified ages; velocities are greater at ages 6 and 9 but less at age 12. During the growth spurt, and at menarche, they are taller but not older. Their adult height is greater and is reached later. Their velocity at takeoff is greater but, at peak, smaller; spurt intensity is much lower. Their adolescent growth spurt contributes less to adult height. For all 338 girls (the E as well as the S subgroup), adult height is correlated only with height during the growth spurt and is virtually independent of spurt timing, whereas menarche is strongly correlated with spurt timing and very little with height. Additional indications that menarche is unrelated to size are that E girls at menarche are significantly taller but not older than the S girls, and that 19 prematurely-born girls at menarche are shorter than girls born at full term but the same age.