Existing comment:
Menarche = The first menstrual period of a person.
Average age of menarche in the uS:
1780 -- 17
1877 -- 15
1901 -- 13.9
1948 -- 12.9
2000 -- 12.3
Some Facts:
Not everyone gets a period.
It took doctors a long time to connect periods with reproduction.
Periods are unpredictable. |