Like Girls, Boys Are Now Entering Puberty Earlier

Data from three U.S. office-based research networks using standardized assessments of pubertal development demonstrated a trend toward earlier puberty in girls (Pediatrics 1997; 99:505). Comparable data are now available for boys.

Researchers enrolled 5355 boys from 144 sites between 2005 and 2010. After excluding boys with missing data or who had medical conditions or medication histories that might affect pubertal development, 4131 boys (50% white) remained for analysis. Mean ages (and standard deviations) for reaching Tanner stage 2 genital development (e.g., thinning or reddening of the skin of the scrotum) and pubic hair development and testicular volume ≥3 mL are provided in the table.

Black boys reached stage 2 genital and pubic hair d…