Menarche

The first menstrual cycle, or first menstrual bleeding, in female human beings.

The onset of menstruation.

The initiation of menstruation in adolescent girls, normally occurring between the ages of 11 and 15. The age at menarche has become younger in Western countries, possibly associated with a better general standard of nutrition, and is later in less-developed countries.

Initial menstrual cycle, marking the onset of fertility.

The first menstrual period. Typically, occurs between the ages of 11 and 14.

Beginning of estrus cycles.

The onset of the first menstruation, which marks the beginning of the regular menstrual cycles that signal a woman’s sexual maturity and fertility; also called pubarche.

First menstruation, usually occurring between the ages of 9 and 16.

Onset of regular menstrual cycle, with usual onset at approximately 13 years of age.

The start of the menstrual periods. This usually happens between the ages of 10 and 17 years.

The start of menstruation. The average age at which it occurs in British females is 12-5 years a year or two after the first physical indications of puberty appear. There is considerable racial and geographical variation.

The initial menstrual period, normally occurring between the 9th and 17th year.

Menarche is the start of a young female’s menstrual cycle. Menarche is usually experienced between 11 and 12 years of age.

The initiation of the menstrual cycle. Menarche typically takes place at approximately 12 or 13 years of age, occurring two years after the commencement of puberty.