In the late 1980s, Marcia Herman-Giddens, then a physician’s associate in the pediatric department of the Duke University Medical Center, started noticing that an awful lot of 8- and 9-year-olds in her clinic had sprouted pubic hair and breasts. The medical wisdom, at that time, based on a landmark 1960 study of institutionalized British children, was that puberty began, on average, for girls at age 11. But that was not what Herman-Giddens was seeing. So she started collecting data, eventually leading a study with the American Academy of Pediatrics that sampled 17,000 girls, finding that among white girls, the average age of breast budding was 9.96. Among black girls, it was 8.87.
When Herman-Giddens published these numbers, in 1997 in Pediatrics, she set off a social and endocrinological firestorm. “I had no idea it would be so huge,” Herman-Giddens told me recently….
Now most researchers seem to agree on one thing: Breast budding in girls is starting earlier. The debate has shifted to what this means. Puberty, in girls, involves three events: the growth of breasts, the growth of pubic hair and a first period. Typically the changes unfold in that order, and the procÂess takes about two years. But the data show a confounding pattern. While studies have shown that the average age of breast budding has fallen significantly since the 1970s, the average age of first period, or menarche, has remained fairly constant, dropping to only 12.5 from 12.8 years. Why would puberty be starting earlier yet ending more or less at the same time?
I wonder if there is a correlation between the start of puberty coming earlier and earlier and all the estrogen floating around due to women medicating themselves with the pill. As for menarche staying rather constant, I would guess there is some unknown factor independent of hormones playing a part.