Normal Pubertal Development

Males

1. prepubertal
2. testes enlarge > 4 cc, and slight reddening of scrotal skin. Pubic hair is long, straight, sparse at base of penis
3. penis, testes and scrotum grows. Pubic hair is darker, curlier, increased distribution.
4. penis, testes and scrotum grows. Penis grows in breadth. Pubic hair is adult type but no extension to thighs
5. adult genitalia. Pubic hair to medial thighs and lower abdomen

Females

1. prepubertal
2. enlargement of areola, elevation of breast and papilla (breast bud). Pubic hair long, straight, sparse, along labia
3. further enlargement of breast/area, no separation of contour. Pubic hair darker, curlier, increased distribution
4. areola and papilla form second mound above breast. Adult-type pubic hair, no extension to medial thigh
5. mature breast. pubic hair in inverse triangle with spread to medial thighs

Order of development: females (average age in years in parenthesis for Caucasian and African American):
1. Breast budding (thelarche) is usually first sign (9.9, 8.9)
2. Pubic hair (pubarche) may be initial sign in 15% (10.5, 8.8)
3. peak height velocity is (12.2)
4. Menarche occurs about 2 years (range 1-5yrs) after thelarche (12.9, 12.2)
5. Note: (you do not complete breast, testicle, genital, or pubic hair development until after reaching peak height velocity)

Order of development: males (average age in years in parenthesis)
1. testicular enlargement is earliest sign (11.8)
2. pubic hair (12.2)
3. genitalia (13)
4. peak height velocity occurs at average age of 14 years (13.8)
5. Note: (you do not complete breast, testicle, genital, or pubic hair development until after reaching peak height velocity)

Female Breast development:
I - preadolescent: there is elevation of the papilla only
II - breast bud stage: there is elevation of the breast and the papilla as a small mound
III - breast and areola are both enlarged and elevation is more than in stage II
IV - the areola and papilla form a secondary mound projecting above the contour of the breast
V - mature: the papilla only projects, with the areola recessed to the general contour of the breast

Pubic hair development, Male or Female
I - preadolescent: the vellus over the pubes is not further developed than that over the abdominal wall
II - sparse growth of long, slightly pigmented, straight or slightly curled hair, chiefly at the base of the penis or along the labia
III - the hair is considerably darker, coarser and more curled. It spreads sparsely over the junction of the pube
IV - hair is now adult in type but the area covered is still considerably smaller than in the adult (no spread to the medial surface of the thighs)
V - hair adult in quantity and type with spread to the medial surface of the thighs

Male Genital development
I - preadolescent: testes, scrotum, and penis are about the same size and shape as early childhood
II - scrotum and testes are slightly enlarged. Skin of the scrotum is reddened and changed in texture. There is little or no enlargement of penis at this stage.
III - penis is slightly enlarged (mainly in length). Testes and scrotum are further enlarged.
IV - penis is further enlarged, with growth in breadth and development of the glans. Scrotal skin is darker than stage III.
V - genitalia are adult in size and shape

When to be concerned

• Males considered precocious if sexual development before 9 years
• Females used to be considered precocious if before 8 years
• some data suggest that breast development before 7 yrs in Caucasians and before 6 yrs in African-Americans may be more appropriate criteria
• one should consider family history, growth velocity, bone age, rate of pubertal progression, etc. for those between 6-8 years of age
• menarche has been reported in 2% of African-Americans by 7 yrs of age
• mean menarchal age, however, has not changed (12.2y AA; 12.9y C)

Hormones

1. Skeletal maturation parallels progression of chronologic age under influence of growth and thyroid hormones, estrogens, and androgens.
2. HPG axis active in neonatal/infancy period but then quiescent between 2-8 years of age due to inhibitory influences. Still, however, have pulsatile release of low amounts of GnRH, measurably increased nocturnal secretion of LH, and GnRH-stimulated secretion of LH and FSH
3. Onset of puberty characterized hormonally by:
   • increase in frequency and amplitude of GnRH pulse generator causing rise in basal serum LH and FSH
   • augmentation of nocturnal LH secretion
   • increase in LH secretory response to exogenous GnRH
   • in females, FSH secretory response to GnRH declines, and LH/FSH ratio increases
4. Gonadarche manifested by:
   • increased secretion of estradiol in girls and testosterone in males
   • in females, cyclic pattern of HPG develops as ovarian oogenesis and ovulation mature
   • adrenarche begins at 6-8 years with increase in adrenal androgens (DHEA & DHEAS)
   • marked increase in GH secretion with puberty

Root, AW. Precocious Puberty. Pediatrics in Review 2000. 21;1:10-19
CHLA Board Review 2005