Accelerated early childhood growth associates with the development of earlier adrenarche and puberty

Context Small birth size and increased postnatal growth have been associated with earlier timing of adrenarche and puberty, but it is not well known whether these factors alone or together lead to earlier maturation. Objective To search for different growth trajectories using a clustering approach to analyze the effects of birth size and postnatal growth on adrenarchal and pubertal development. Design and participants Altogether 351 children (48% girls) were examined prospectively at age 6-9 and 9-11 years. Birth and early growth data were collected retrospectively. Main outcome measures Clinical signs of adrenarche and puberty, and serum androgen concentrations (dehydroepiandrosterone, dehydroepiandrosterone sulfate, androstenedione, testosterone). Results We detected four clusters with different birth sizes and postnatal growth trajectories: 1) children with average birth size and increased postnatal growth (AI), 2) children with small birth size and increased postnatal growth (SI), 3) children with average birth size and postnatal growth (AA), and 4) children with small birth size and average postnatal growth (SA). Thelarche at age 9-11 was most common and serum androgens at age 6-9 and 9-11 years were highest in girls belonging to AI and SI groups. Similar patterns in the onset of puberty and in androgen levels were not seen in SA group. Conclusions Increased early growth and weight gain predict higher serum androgen concentrations and earlier onset of puberty in girls. Adrenarche and puberty do not appear to be shifted earlier in children with small birth size who do not have catch-up growth.