There is unexpectedly large variation in height growth in girls after their first period. Every second girl grows either more or less in length than the 6-8 centimeters that is considered standard.

Girls in the U.S. are getting their first menstrual period about 6 months earlier on average than they did in the 1950s and '60s. And more girls are beginning menstruation before the age of 9, which ...

Girls in the United States are getting their periods earlier, and it's taking longer for them to become regular, according to a study. The age at which women get their first period, known ...

Girls are getting their first periods at a younger age, according to a new study. Research conducted by Harvard University's public health school found that, in the US, the time of a person's first ...

Menstruation is a natural biological process experienced by nearly half the global population. Yet, for many girls, the first period arrives as a surprise—often misunderstood, feared, or even ...

A female’s first menstrual period, known as menarche, occurs during puberty. Menstruation indicates that the body is mature enough for reproduction. About 98% of girls begin their periods by age 15.

Share on Pinterest Research shows that girls are getting their first period earlier than in previous decades, which may be tied to rising obesity rates. MStudioImages/Getty Images A new study finds ...

Girls in the U.S. are getting their first period earlier than in decades past. Researchers say there are multiple factors causing early puberty, including obesity and environmental pollutants. Girls ...