Back when many of today's parents were in elementary school, if a girl started wearing a training bra in fourth grade, that was considered "on the early side." These days, however, many girls are dealing with the signs of puberty at an even earlier age — causing concern for both the girls and their parents.
By age 8, forty eight percent of African American girls and fifteen percent of Caucasian girls are showing clear signs of puberty, according to Diana Zuckerman, Ph.D., president of the National Re- search Center for Women and Families in Washington D.C. (There hasn't been a significant shift in the age of onset of puberty in boys, experts say.)
Today, a girl of 7 or 8 who is starting to develop breasts or pubic hair is considered "on the early end of normal," says Paul Kaplowitz, M.D., Ph.D., a professor of pediatrics and chair of the department of endocrinology at Children's National Medical Center in Washington, D.C. Kaplowitz is also the author of "Early Puberty in Girls" (Ballantine), a book that goes a long way toward easing parents' anxiety.
Perhaps even more important than when puberty starts is what Kaplowitz calls "the tempo of puberty; how fast it progresses." Sometimes a 6-year-old girl can have the beginnings of breast development, but it doesn't progress beyond that stage for several years, he explains. That scenario causes less concern than that of an 8-year-old girl who is rapidly progressing through puberty.
What Causes Early Puberty?
Often, a girl follows the genetic pattern of her mother, Kaplowitz says. If mom went through puberty early, her daughter likely will, too. But that has been the case for generations. What is causing so many girls today to begin developing breast and pubic hair at younger ages?
Obesity has an important connection to early puberty in girls, according to a study published in the medical journal Pediatrics. The study of 17,000 girls found that 6- to 9-year-old girls who had started developing breasts or pubic hair were significantly more overweight than girls of the same age who had not.
Researchers from the Breast Cancer Fund noted, in a Sept. 2007 report, "The Falling Age of Puberty in Girls: What We Know, What We Need to Know," that "there is sufficient evidence for the contribution (direct or indirect) of body mass to pubertal timing in girls to support efforts to combat childhood obesity."
The percentage of children ages 6 to 11 who are overweight has nearly doubled since the late 1970's, according to U.S. government statistics that note that some 20 to 25 percent of kids are either overweight or close to being overweight.
Scientists are on the hunt for additional possible causes, and are looking at everything from phthalates (certain types of industrial chemical compounds) in cosmetics and plastics to hormones in meat and milk. This possibility needs to be extensively studied in humans, says Zuckerman. But "there is clear evidence that pesticides and some other exposures interfere with hormones and can cause reproductive abnormalities in animals," she notes. Zuckerman adds that she is concerned that prenatal exposure to pesticides, hormones and phthalates may be a contributing factor in early puberty.
Periods Not Arriving Earlier
Given that many girls develop breast tissue and pubic hair at earlier ages these days, it's logical for parents to assume that girls' periods are starting earlier, too. But according to Zuckerman, the average age of first menstruation is similar to what it was a generation ago: 12.1-years-old for African Americans and 12.8 for Caucasians.
Even if a girl's period does start on the early side, Kaplowitz says most girls are able to handle having a period (including the hygiene-related tasks) by age 10. At age 9 or younger, it is important for the doctor and the parents to assess the girl's readiness to handle menstruation, both emotion-ally and from a practical standpoint, he adds.
It helps for parents to be given a timetable, Kaplowitz says, noting that after the onset of breast development, the first period will generally arrive within 2 to 3 years. This knowledge allows parents to talk with their daughter about her changing body and to prepare her for the start of menstruation.
Menstruation & Growth: What's The Connection?
A girl's growth stops approximately 2 years after the onset of menstruation, according to Kaplowitz. But this period of growth is longer for girls who start menstruation early (before age 12) than for those who start late (age 14 or later), he says.
"Most girls grow between 1 and 4 inches after they reach menarche," explains Kaplowitz. "Men-struation has no direct effect on growth, but it tends to occur after about 2 years of increasing estrogen production, with its effect on the uterus. The rising estrogen levels also cause changes in the maturation of the growth plate, which causes cartilage to be changed into bone." Once that process is complete, says Kaplowitz, "we say that the growth plates have fused and growth stops."
"Girls and guys are very aware of who has hit puberty and who hasn't, and no one feels comfortable being way ahead or way behind the pack," says Carol Weston, author of Girltalk: "All the Stuff Your Sister Never Told You" (HarperCollins).
"Girls will become self-conscious about leg hair, breast size and whether they've 'started," she says. "It's best when a parent can say, in a comfortable, matter-of-fact way, 'Everyone grows up, but friends grow at different rates. Puberty has nothing to do with emotional maturity, so don't let this affect your friendships.'"
Try to keep the "birds-and-bees" conversations low-key, experts suggest. "It helps if a mother is able to go shopping with her daughter and casually say, 'Hey, want to try on some bras?' since many girls are too embarrassed to articulate the question and are dying for Mom to bring it up," Weston says.
It also helps if parents have told their daughters that if they get their period in school, all they have to do is raise their hand and say that they need to go to the nurse, Weston says. "Better yet, pack some pads in a small, opaque case and tell your daughter to leave them in the back of her locker," she adds. To an adult this may sound simplistic, she says, but to a young girl, it provides peace of mind.
In the end, parents set the tone for how their daughter will handle the potential physical, emotional and social challenges of early puberty, Kaplowitz says. By remaining calm and matter-of fact, your daughter will see that puberty, even if it's arriving a bit early for her, is just another part of life.
Should You Consult an Endocrinologist?
When are the signs of early puberty normal and when do they indicate the need for a visit to an endocrinologist? (Endocrinologists are concerned with the metabolism, physiology and disorders of the endocrine system.) If you notice rapid changes over a 4-to-6-month period or if you see that your child is crossing over into higher percentiles on her growth chart, as opposed to tracking along the same percentile, talk with your child's doctor, Kaplowitz suggests.
The doctor may suggest an evaluation by an endocrinologist. Zuckerman notes that parents "should always take their child to an endocrinologist if the child's development is very early or very late compared to most peers."
To locate an endocrinologist, visit the American Association of Clinical Endocrinologists' Web site (www.aace.com). At the home page, click on "Find an Endocrinologist."