Menarche

The word menarche is derived from the Greek words me–n, month, and arche–, beginning. It is the term used to refer to the first menstrual period. This first sign that menstruation has begun is governed by a complex set of biological processes, genetic information, and psychosocial factors. In the human female, the usual age for menarche is between ages eleven and twelve (Martini 1992). Other studies, however, report figures between twelve and thirteen (Boaz and Almquist 1997).

Variables that influence the onset of menarche include body build or body mass, critical weight, height/weight ratio, skeletal maturation, and percentage of body fat. Other correlates are health history, protein intake, amount of daily exercise, and familial trends.