Abstract
AIM Fetal androgens influence fetal growth as well as postnatal neurocognitive ability. However, to our knowledge, no published study has prospectively examined the impact of early-life androgens on infant brain growth. We report the association between circulating fetal androgen levels, measured from umbilical-cord blood at birth, and a proxy measure of brain growth: head circumference.
METHOD Participants were 82 unselected female infants from a large representative birth cohort (mean gestational age 39.4wks, SD 1.7). Umbilical-cord blood was obtained at birth and analysed for androgen concentrations (total testosterone, androstenedione, dehyrdroepiandrosterone, and its sulphated metabolite). Head circumference and two other measures of growth - weight (mean 3311.4g, SD 461.3) and length - were measured within 3 days of birth and again at approximately 1 year of age (mean age 13.1mo, SD 1.1).
RESULTS Multivariate linear regressions found an inverse association between levels of free testosterone and growth in head circumference (correlation = -.24), even when adjusting for sociodemographic/obstetric covariates and head size at birth. Growth in weight and length could not be predicted by free testosterone concentration.
INTERPRETATION This is the first report of an association between prenatal androgen levels and postnatal growth in head circumference. These findings suggest that early-life androgens may impact brain development during infancy.
