Early puberty-menarche after precocious pubarche: relation to prenatal growth.

OBJECTIVE: Girls with precocious pubarche (PP; pubic hair at <8 years of age) as a result of an early or amplified adrenarche (high dehydroepiandrosterone-sulfate [DHEAS]) tend to be hyperinsulinemic, in particular when born with low birth weight (LBW). The objective of this study was to assess the interrelationship among prenatal growth, PP, the timing of puberty-menarche, and adult stature.
METHODS: We studied 187 PP girls longitudinally: (1) at birth, (2) in prepuberty, (3) at onset of puberty, (4) at menarche, and (5) on reaching adult stature. This PP cohort was divided into subgroups of higher birth weight (>0 SD), intermediate birth weight (0 to -2 SD), and lower birth weight (less than -2 SD).
RESULTS: At the time of PP diagnosis, age, bone age, and BMI were similar across birth weight subgroups; circulating sex hormone-binding globulin and body height were reduced in PP girls with lower birth weight, and these remained so throughout pubertal development. Onset of puberty occurred earlier in PP girls with lower birth weight; so did menarche. Adult height differed by an average of 6.5 cm (approximately 1 SD) between the upper and lower birth weight subgroups; this difference was essentially achieved before puberty and even before PP. Menarche before age 12.0 years was twofold more prevalent in PP girls than in control subjects. Among PP girls, age at menarche was advanced by 8 to 10 months in lower versus higher birth weight girls. Menarche before age 12.0 years was threefold more prevalent among LBW-PP girls than in control subjects (approximately 75% vs approximately 25%).
CONCLUSIONS: The link between prenatal growth restraint and early menarche is herewith extended to PP girls. In particular LBW-PP girls may become a target group for interventions directed toward normalization of pubertal onset and progression.