Puberty-Defining Normal and Understanding Abnormal

Species Comparison of Postnatal Development of the Female Reproductive System

“…The dictionary definitions of puberty and sexually mature highlight the potential confusion in using these terms, as both use the ability to reproduce as a defining feature. A recent definition of puberty that is considered useful and also helps define sexual maturity is “the period of transition from childhood to adulthood, with completion of the appearance of adult features, secondary sexual characteristics and the ability to reproduce considered the end of this period” (De Silva and Tschirhart, ).…”

“…Other terminology prescribed to physiological aspects of the developing reproductive system is the family of terms using the suffix “arche,” or the “beginning of.” In humans, the appropriate sequence of puberty in the female is adrenarche (beginning of pubertal adrenal development marked as increased levels of adrenal androgens signaling early puberty), gonadarche (beginning of significant ovarian steroid production), thelarche (beginning of postnatal breast development), and then menarche (first menstrual bleeding) (Belgorosky et al, ; De Silva and Tschirhart, ). Puberty is the coordinated sequence of biochemical and physiologic events including adrenarche and gonadarche which result in the growth spurt of adolescence, development of secondary sex characteristics, and reproductive capability.…”

“…Then the first appearance of pubic hair (pubarche), which coincides with the maturation of the adrenal cortex (adrenarche), commonly around ages 9 to 13 years. The classic physical hallmark of puberty, menarche (first menstrual bleeding), occurs at approximately age 12 to 13 years (De Silva et al, ), immediately followed by menstrual cycles that are irregular and typically anovulatory (a time sometimes called adolescent sterility). This is followed by a maximum pubertal growth spurt, which includes significant weight gain and enlargement of female sex organs (uterus, ovaries, labia, and clitoris), which ceases around age 15 years.…”

“…Female body weight during development is recognized as an important factor for the timing of reproductive developmental events, both clinically and in animal species, generally with an association of increased body weight and earlier onset of puberty, and vice versa. There are multiple causes associated with early puberty (thyroid abnormalities, idiopathic) or late puberty (such as excessive exercise or chronic disease), which can lead to adverse outcomes later in life such as obesity, diabetes, and cardiovascular disease (Day et al, ; De Silva and Tschirhart, ; Villamor and Jansen, ). The attainment of a critical body weight, or amount of body fat does not trigger puberty in female rats (Glass et al, ), but accumulation of body fat is a component, as excess calories not needed for rapid growth can then be stored.…”

The Neurological, Multisystemic, PolyGenomic and Multipathological Basis of Aging (the ‘Autonomic’ Hypothesis)

“…O p e n H U B f o r S c i e n t i f i c R e s e a r c h Citation: Ewing How can we explain that (i) a child's exposure to stressful experiences can influence the time when puberty takes place [108][109][110]; (ii) alcoholic intake during pregnancy increases the risk of abortion or birth defects [111,112]; (iii) altered systemic stability during pregnancy e.g. of intercellular pH, elevated blood pressure, levels of blood glucose(diabetes); influences childbirth outcomes [113][114][115]; (iv)an inadequate diet during childhood influences our growth and development [116]; (v) smoking during pregnancy can result in abortion or birth defects [117]?…”