menarche

Last reviewed 04/2023

In 95% of girls the onset of puberty is from 8 to 13 years. The first event is most often breast formation in 80%, but pubic and axillary hair growth is first in 20%. Breast development may continue until age 18 years and pubic hair grows until age 17 years.

Menarche is a late feature of female puberty. It has a mean age of onset of 13 years, ranging from 11 to 15 years.

The age at which menarche occurs is closely correlated with skeletal maturity and it is very unusual for a girl to be amenorrhoeic with a bone age of over 15 years.