Growing Pains

By Christine Gorman

Most girls don't start developing breasts until around the fifth grade. But as many pediatricians, parents and teachers will tell you, this first sign of puberty seems to be occurring more often among six-year-olds and seven-year-olds than ever before. (Boys, as far as anyone can tell, are still growing up at their usual, slower pace.) Nobody can explain this speedup. Some even question whether it's real or anything abnormal. But if you suspect your first- or second-grader is blossoming too early, some basic information may help you sort through the confusion.

Researchers don't know exactly how a child's body decides to start the two-to-three-year process of becoming a biological adult. But they do know the first stage begins in the brain, when a chemical signal, called gonadotropin-releasing hormone, unleashes a series of biochemical reactions in the body. Soon girls will notice a swelling of tissue around the nipples. (Menstruation usually begins a year or two later.) In boys, the penis and testes start to grow larger.

For decades, pediatric textbooks defined precocious puberty as a rare condition that occurs before age eight in girls and nine in boys. Then along came a study of 17,000 girls, published in 1997, that found 7% of white girls and 27% of African-American girls begin developing breasts or pubic hair by age seven. Intriguingly, the average age of menstruation still hovers around 12.

There are some statistical problems with the study that keep it from being considered definitive. But it raised a lot of concern. Folks who like to blame the agro-food industry quickly argued that pesticides in food might have a hormone-like effect on children's bodies. Many pediatric endocrinologists, however, believe the suspected change has more to do with the extraordinary increase in childhood obesity over the past two decades. Fat cells produce leptin, a protein known to help trigger puberty. With more fat cells churning out leptin, earlier puberty would seem highly likely.

Now comes the big question: Should you try to stop early puberty in its tracks? Many girls who enter puberty at age seven or so seem to progress through it slowly and grow up none the worse for it. The important thing for parents is to make sure their children understand that what they're going through is natural and to prepare them for the mood swings and teasing they may endure.

Girls younger than seven or those whose puberty seems to be accelerating--producing, for example, adult-size breasts--may require medical treatment. Sometimes the problem is a tumor. Other times there appears to be no physical cause. Current treatment consists of monthly injections of a powerful gonadotropin-blocking drug called Lupron. Cost: $6,000 to $10,000 a year. Opting for treatment is not a decision to be taken lightly, so if your doctor recommends such a course, get a second opinion.

Even if your child hasn't reached puberty, talk with him or her about what lies ahead. If you'd like some help, check out the excellent picture book It's So Amazing! by Robie Harris and Michael Emberley (Candlewick; $21.99), which is geared to boys and girls ages seven to nine. It could help prepare your son or daughter--as well as reassure you.

For more information on early puberty, visit time.com/personal You can send e-mail to Christine at gorman@time.com