Menarche

from Wikipedia, the free encyclopedia

Under menarche ( ancient Greek μήν MEN "month" and ἀρχή Ark "beginning") is defined as the first occurrence of menstruation , d. H. the onset of menstruation, in puberty .

Menarche takes place during pubertal development, but does not clearly signal reproductive ability in the sense of an ovulatory cycle, as the first menstrual periods are usually anovulatory hormone withdrawal bleeding that does not involve ovulation . A regular ovulation cycle usually occurs after one and a half to two years.

Fluctuations at the time of occurrence

Menarche is particularly suitable as a discrete feature for describing the development of puberty, such as spermarche in boys. The timing depends on ethnic , geographical, individual and nutritional factors. For girls, the period between the appearance of the first signs of puberty ( pubic hair and breast growth ) and menarche is on average between 2.2 and 2.7 years, but can vary between less than a year and more than six years. In Germany, menarche occurs in most girls between the ages of 10 and 16. In the early 19th century, it was two years later. A drastic shift in the timing of menarche then occurred for the first time around 1850. Since then, it has taken place three to four months earlier on average every decade. The differences in age of maturity between population groups appear primarily as a result of environmental conditions and specific nutritional patterns, but also influenced by hygienic-sanitary or medical culture conditions. It has been shown, for example, that the menar age in Europe and the USA is between 11.5 and 14.5 years.

Cases have been documented in which menarche occurred before the age of six. Given the same living conditions in the populations, genetic differences also explain the spread. It is discussed that reaching a certain percentage of body fat is decisive for the onset of puberty (> 17% percentage), so that young competitive athletes and underweight people show retarded maturation. The " Critical Weight menarche hypothesis " ( critical weight-menarche hypothesis ), said that the menarche with apparently reaching a body weight correlated kg of 48, but could not be confirmed later. On the other hand, there was also a connection with body size.

Web links

Wiktionary: Menarche  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ Children and their Primary Schools. Part Two: The Growth of the Child Plowden Report, 1967 - accessed August 23, 2019
  2. ↑ Gerd Mietzel: Ways in Developmental Psychology. Volume 1: Childhood and Adolescence. 4th, completely revised edition, Beltz Psychologie Verlag Union, Weinheim 2002, ISBN 3-621-27477-4 , p. 354 ( first menstrual period. In the Google book search).
  3. ↑ Hans-Heinrich Thiemann, Inna Nitz, Andreas Schmeling et al. (Ed.): X-ray atlas of the normal hand in childhood. Volume VII, 3rd edition, Thieme, Stuttgart 2006, ISBN 3-13-766603-1 , ( 9 - General findings, menarche in the Google book search).
  4. ^ S. Steingraber: The falling age of puberty In US girls. Calif Breast Cancer Fund, San Francisco 2007 ( breastcancerfund.org ( memento of the original from December 27, 2010 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note . PDF; 1.3 MB). @1@ 2Template: Webachiv / IABot / www.breastcancerfund.org
  5. ^ Walter Stoeckel: Textbook of gynecology. 11th edition, Hirzel, Leipzig 1947, pp. 259f. For his part, he gives as the source for the case described: P. Chaschinsky, S. Jerschow: About "Pubertas praecox" and pregnancy with timely birth in a six-year-old girl. In: Zentralblatt für Gynäkologie . (Zbl. Gynäk.) 1933, No. 38, Barth, Leipzig 1933, pp. 2252-2256.
  6. ↑ Nicolas de Roux: Human genetics of pubertal onset . In: Endocrine Abstracts. 2008, No. 16, p. 29. 4.
  7. ↑ HS Mumby et al. a .: Mendelian randomization study of childhood BMI and early menarche. In: Journal of Obesity. 2011, Volume 2011, Article ID: 180729, doi: 10.1155 / 2011/180729 .
  8. ↑ Rose E. Frisch: Body fat, menarche, fitness and fertility . In: Human Reproduction. 1987, Vol. 2, No. 6, pp. 521-533.
  9. ↑ Ora Hirsch Pescovitz, Emily C. Walvoord (Ed.): When puberty is precocious: scientific and clinical aspects. In: Contemporary Endocrinology. Humana Press, Totowa (NJ) 2007, ISBN 978-1-58829-742-6 .
  10. ↑ Rose E. Frisch, Roger Revelle: Height and Weight at Menarche and a Hypothesis of Menarche. In: Archives of Disease in Childhood. (Arch Dis Child) 1971, No. 46, pp. 695-701, doi: 10.1136 / adc.46.249.695 ( adc.bmj.com full text PDF).
  11. ↑ Shu-Hui Chang, Shinn-Jia Tzeng, Jung-Yu Cheng, Wei-Chu Chie: Height and Weight Change Across Menarche of Schoolgirls With Early Menarche. In: JAMA Pediatrics. (Formerly: Archives of Pediatrics and Adolescent Medicine. [Arch Pediatr Adolesc Med.]) Volume 154, No. 6, September 1, 2000, pp. 880-884, doi: 10.1001 / archpedi.154.9.880 .