Puberty starting earlier in boys, study suggests

A large study released by the American Academy of Pediatrics suggests that boys are entering puberty earlier now than several decades ago— or at least earlier than the time frame doctors have historically used as a benchmark.

The study, widely considered the most reliable attempt to measure puberty in U. S. boys, estimates that boys are showing signs of puberty six months to two years earlier than was reported in previous research, which historically taught that 11 ½ as the general age puberty began in boys.

But experts cautioned that because previous studies were smaller or used different approaches, it is difficult to say how much earlier boysmight be developing.

The study echoes research on girls, which has now established a scientific consensus that they are showing breast development earlier than in the past.

Not sure what it means

The study, which was announced at the Academy of Pediatrics national conference Saturday and published online in the journal Pediatrics, did not try to determine what might be causing earlier puberty, although it mentioned changes in diet, less physical activity and other environmental factors as possibilities.

Experts said that without further research, implications for boys are unclear.

“This should perhaps set a standard going forward for being very attentive to puberty in boys and being mindful that they’re developing earlier,” said Dolores Lamb, amolecular endocrinologist at Houston’s Baylor College ofMedicine and president of the American Society for Reproductive Medicine. She was not involved in the study.

Praising the study as well done, she said, “Whether the difference is as large as what they say on some papers 40 years ago is not clear.”

However, she added, “this is going to be incredibly useful to pediatricians and urologists.”

The study also found that African- American boys began puberty earlier than whites and Hispanics, a result that other studies have shown also applies to AfricanAmerican girls. Researchers said that difference is most likely driven by the role of genes in puberty.

On average, black boys in the study showed signs of puberty, primarily identified as growth of the testicles, at a little older than 9, while white and Hispanic boys were a little older than 10.

Several experts said the study should not be seized upon as cause for alarm but rather as a way to help parents and doctors gauge what to be aware of in boys’ development and whether to start conversations about social issues sooner.

For the study, researchers enlisted about 200 pediatricians in 41 states to record information on 4,131 healthy boys ages 6- 16 during their wellchild exams. Physicians were trained to use an orchidometer, a string of oval wooden or plastic beads of increasing size that are compared against the size of the testicles. Urologists use orchidometers to measure testicular volume when men have fertility concerns.

Taboo question

The study’s lead author, Marcia Herman- Giddens, a child and maternal health specialist at University of North Carolina Chapel Hill, said she originally proposed an additional measure used in Europe: identifying through urinalysis, or by asking if boys had begun to ejaculate.

But she said that urinalysis would havemade the study expensive, and colleagues “just freaked out” about the prospect of asking boys about ejaculation, wondering, “How would a child understand that?”

Herman- Giddens led a large study on girls’ puberty in 1997, and its conclusion that girls were developing earlier generated great controversy. Now, though, experts generally agree that subsequent research has shown breast development as young as 7 or 8.

With menstruation, however, studies conflict: Some suggest it is starting earlier, while others suggest the age has not changed much.

Experts said this could mean that puberty is beginning sooner but lasting longer or that different physiological processes underlie breast development and menstruation.