Menarche (/məˈnɑːrki/ mə-NAR-kee; from Ancient Greek μήν (mēn) 'month' and ἀρχή (arkhē) 'beginning') is the first menstrual cycle, or first menstrual bleeding...

and Pasquet, P. "Evolution de l'âge d'apparition des premières règles (ménarche) en France". Biométrie Humaine (1978), 13, 35–43. Gluckman PD, Hanson MA...

sexual characteristics by age 13 with no menarche or normal secondary sexual characteristics but no menarche by 15 years of age. It may be caused by developmental...

normally last between 21 and 35 days, with a median length of 28 days. Menarche (the onset of the first period) usually occurs around the age of 12 years;...

body hair growth, breast development and menarche (the onset of menstruation). Most girls go through menarche between ages 12–13, and are then capable...

breast tissue occurs during fetal development. Usually, females experience menarche about two years after thelarche has begun, with complete breast development...

pubic hair due to androgen stimulation), peak height velocity, and finally menarche (the onset of menses), which usually occurs around age 12 or 13. Phillips...

compromised 16- to 20-year-old virgins after menarche. The highest rank comprised 14-year-old virgins before menarche. ("The Role of Sexual Lore in Taoism" begins...

pubertal timing may be influenced by weight, physical activity, and genetics. Menarche, a central event of female puberty, is associated with the father's absence...

PMID 7132642. Frisch RE, Gotz-Welbergen AV, McArthur JW, et al. (1981). "Delayed menarche and amenorrhea of college athletes in relation to age of onset of training"...