When do girls start menstruate ?

In France, first menstruation or "menarche" occurs at around age 13. According to a survey conducted in 1994, half of all girls had already started menstruating at age 13. Most girls (9 out of 10) have their first period between ages 11 and 14.

The age of menarche has been falling over the last two centuries

In the past, girls in Europe had their first period between ages 16 and 18 on average, and likewise in southern countries until quite recently. But the age of menarche has fallen everywhere, and now occurs at age 12 to 13 on average in industrialized countries (figure). The earlier onset of puberty is attributed to better nutrition, education and modern lifestyles, which stimulate children's nervous and hormonal functions. But the causes of this change are still not fully understood.

Will this trend continue?

In recent years the decline has levelled off in several countries (e.g. United States, United Kingdom) and age of menarche has stabilized at between 12.5 and 13.5 years. The same pattern will probably be observed in France as well.

Last update : January 03 2013