There is a growing pattern of children entering puberty at younger ages. Girls who begin menstruating earlier are at risk for more serious health conditions.
Girls have been getting their periods earlier and earlier for more than half a century. And as early onset increased, it has taken longer and longer for menstrual cycles to become regular. Both of those facts carry the possibility of health challenges as the girls get older.
A new study finds that US girls are experiencing their first periods earlier, with factors such as improved nutrition, increased BMI, and environmental exposures potentially driving this trend.