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.
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. 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. 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.