The average age at which U.S. girls usually begin puberty is 10 or 11. But the study, published in the August 9, 2010 issue of Pediatrics, shows a notable spike in the number of girls with some breast growth by age 7 or 8.
The study tracked 1,239 girls between the ages of 6 and 8 from three U.S. cities. Across the board, the results were startling: 10 percent of 7-year-old white girls had some breast development, compared to 5 percent in a 1997 study. And 23 percent of 7-year-old black girls had started developing breasts as compared to 15 percent in the 1997 study.
Physical and Emotional Effects
In addition to the obvious changes that come with the territory – such as breast and hip growth, acne, and mood swings – girls who experience precocious puberty may face these health issues:
- Higher risk of breast cancer. Although this link is still being studied, some research has shown that early puberty may be linked with higher breast cancer risk later in life.
- Shorter stature. Growth in height typically starts to slow down for girls during puberty, so girls who hit it earlier on may not reach the same stature as their peers who get taller before maturing physically.
- Emotional struggles. In addition to feeling anxiety about their monthly period and changing body, girls who hit puberty much sooner than their peers can feel alienated from friends who are experiencing more typical development. Their classmates are likely to notice and point out the changes, and some may even tease and taunt them.
- Young pregnancy. As if a girl in the throes of puberty well before middle school doesn't have enough to handle, there's also the issue of sexuality. Most younger girls haven't had any sex education or discussions with a parent, so they may be clueless about making safe choices. This could potentially affect the rates of teen or even preteen pregnancy.