Increasingly, parents are asking doctors to put the brakes on puberty. That's because girls are developing sexually at younger ages and treatment is available to suppress it.

A landmark study of more than 17,000 girls published three years ago reported that black girls, on average, experience the first signs of puberty between ages 8 and 9. White girls undergo those physical changes by age 10. That's two years earlier for black girls and one year earlier for white girls than previous studies had reported.

For many mothers and fathers, that's far too soon.

"My clinic is full of parents who are worried when they see their little girls are developing breasts or pubic hair," said pediatric endocrinologist Kenneth C. Copeland, M.D., professor of pediatrics at University of Oklahoma Health Science Center.

Early puberty appears to be less common in boys, and when it does occur, it's frequently not diagnosed until it's too late to be treated.

For girls, the physical changes can be both dramatic and traumatic, including mood swings, headaches, development of breasts, and growth of pubic and body hair.

Parents are seeking treatment for their daughters for myriad reasons, including psychosocial ones. Some of them worry that by developing physically too soon, their daughters will have to face teasing from peers and unwanted attention from older males.

Others think "something might be wrong because their daughter is younger than they remember being at that stage of development," said Janice D. Key, M.D., associate professor of pediatrics and director of adolescent medicine at Medical University of South Carolina. "They're concerned that the child is not ready to be a teenager. Parents are saying, 'Slow this down, doc'."

Injections of Lupron, a hormone-suppressing drug originally approved by the Food and Drug Administration in 1985 for treatment of prostate cancer, can fend off puberty in children who develop prematurely. The drug, which costs about $6,000 to $10,000 a year, received approval for use in treating precocious puberty in 1993. But medical intervention raises a host of ethical, social and health issues.

"Even if (puberty does occur) before 8 years old, it may be an extreme variation of normal with no deleterious consequences," said Robert L. Rosenfield, M.D., professor of pediatrics and medicine at University of Chicago Pritzker School of Medicine and University of Chicago Children's Hospital. "Most 6- to 8-year-old children and their families can deal with the psychosocial issues with some guidance. Unfortunately, too many doctors give Lupron. Treatment is too often abused."

The puberty study, published in Pediatrics in April 1997, concluded that girls are maturing sexually at ages younger than the standards used in pediatric practices to determine normal development.

The study defined puberty as precocious when it occurs in girls before age 8 -- age 7 for black girls -- and in boys before age 9. That represents a shift from 30 years ago when puberty was considered premature if it took place in girls at age 10. Recent debate in some pediatric circles has centered on whether to lower the age even further -- to age 6.

Menstruation, however, doesn't appear to be occurring any sooner. The age at first period has hovered around 12 for decades, after falling at a rate of about six months every 50 years for about 150 years.

It's not clear why girls seem to be maturing faster, although diet, obesity, genetics and environmental exposures, such as hormones in food and cosmetic products, are suspected factors.

Treatment is clearly advantageous in cases of true precocious puberty. Children who experience premature development face the risk of an early growth spurt that can shut down too soon, causing them to be abnormally short. However, pubic hair growth without breast development is not considered a sign of early puberty and that condition does not respond to Lupron. Girls generally begin menstruation about two years after the start of breast development.

"Most pediatricians would agree that puberty between 3 to 6 is early and absolutely deserves a full work-up and consideration for treatment," said Francine Kaufman, M.D., head of pediatric endocrinology at Children's Hospital Los Angeles. A work-up could include testing of the pituitary gland and ovaries, and a determination of bone age.

The gray area is whether to treat children between 6 and 8.

"Primary care providers should evaluate (development) within the broader context of what is going on with the child," Kaufman said. "In a big or heavy girl, or in one in which there is a family history, early puberty is likely to be completely normal. I would view it differently in a short, thin girl without a family history."

But some doctors think there are legitimate non-medical reasons to treat, such as "to preserve childhood years". Floyd Culler, M.D., professor of pediatrics at University of California in Irvine, said he's comfortable treating a child solely because she's "not ready to bear childhood in an adult body."

The key to determining the right course is for parents, children and doctors to talk to each other, said Jennifer Johnson, M.D., chairman of the American Academy of Pediatrics' Section on Adolescent Health. Incredibly, many parents still don't initiate a dialogue with their children about "the facts of life". Twice as many parents perceive they've talked to their kids than surveys of their children indicate, she said.

Moreover, many parents don't remember when they started puberty and so lack an accurate gauge of what's typical. "What I've encountered is parents saying, 'my daughter is already starting puberty, is that normal?' Parents want to know what's normal," Johnson said.

Doctors have their work cut out for them. "We need to talk to parents about when to expect puberty," she said. "It's more important now for parents to talk to kids early."

In fact, Johnson sees a connection between the inability of parents to talk with their children about sexual development and requests for medicine "to fix" the perceived problem. That concerns her because the healthy emotional development of girls is also at stake.

Medical intervention can "send a message to girls, and that message is: 'We can't trust you with what your body is doing'," said Johnson, the mother of an 11-year-old girl. "While it is certainly true that early-maturing girls can have difficulties, my initial reaction is that unless it's an extreme case, I'd rather educate them about how they can handle it."

(c) 2000, Deborah Shelton. American Medical News. Distributed by Los Angeles Times Syndicate