Paediatrics: Normal puberty

Normal puberty

Puberty is a well-defined sequence of physical and physiological changes occurring during the adolescent years that culminates in attainment of full physical and sexual maturity.

·  Nocturnal, pulsatile, secretion of the hormone luteinizing hormone-releasing hormone (LHRH) by the hypothalamus is the first step in the imitation of puberty. This results in the pulsatile secretion of the gonadotrophin hormones LH and FSH by the anterior pituitary gland. LH stimulates sex hormone production from the gonads.

·  The age of onset of puberty is earlier in females (mean (range) 10.5 (8.5–12.5)yrs) compared to males (12.0 (10–13.5)yrs). In each sex, puberty progresses in an orderly or ‘consonant’ manner through distinct stages (see Table 13.1).

·  In females, the first sign of puberty is breast development, followed by pubic hair growth and growth acceleration. Menarche (the onset of menstruation) occurs, on average, 2.5yrs after the start of puberty (average age 13.0yrs).

·  In males, the first sign of puberty is an enlargement of testicular size to greater than 4mL in volume. Pubic hair development and growth acceleration follow.

Pubertal growth spurt

In females, peak growth (height) velocity occurs relatively earlier in girls (Tanner stage 2–3) compared with boys (Tanner stage 3–4; testicular vol-umes 10–12mL).

Note: The age of onset of puberty varies slightly between children of dif-ferent races. In Afro-Caribbean and African-American children, average age of onset of puberty may be earlier compared with that of White children.