The striking physical and endocrine changes in puberty should be considered to be a part of the continuum of development between the fetus and adulthood. Hypothalamic control mechanisms, operative during intrauterine existence but suppressed during childhood, reactivate during puberty and lead to increased secretion of gonadal sex steroids which result in the development of secondary sexual characteristics, the pubertal growth spurt, and the attainment of fertility. The age of onset of puberty, as reflected by age of menarche, is under the control of both endogenous and exogenous factors. Historical records reveal a decrease in the age of menarche in western countries of four months each decade between 1850 to 1950; this secular trend appears to be the result of improvement of socioeconomic factors. There has been no further modification in the age of menarche in the United States and in many western European countries over the last two decades. Other factors controlling menarche include obesity (moderate obesity, up to 30% over normal weight for age, leads to advanced menarche whereas severe obesity may delay menarche), chronic disease and attendant malnutrition (delayed menarche), and blindness (advanced menarche). Genetic influences, demonstrated by concordance in mother daughter pairs and within ethnic populations, appear to play a major role in age of menarche when disorders of nutrition and suboptimal socioeconomic conditions are improved.
|Original language||English (US)|
|Number of pages||26|
|Journal||Pediatric Clinics of North America|
|State||Published - 1979|
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health