title: Free testosterone levels in umbilical-cord blood predict infant head circumference in females.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Participants were 82 unselected female infants from a large representative birth cohort (mean gestational age 39.4 wks, 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 3311.4 g, SD 461.3) and length - were measured within 3 days of birth and again at approximately 1 year of age (mean age 13.1 mo, 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia. awhitehouse@ichr.uwa.edu.au
authors.forename: Andrew J O
authors.initials: AJ
authors.lastname: Whitehouse
authors.forename: Murray T
authors.initials: MT
authors.lastname: Maybery
authors.forename: Roger
authors.initials: R
authors.lastname: Hart
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Sloboda
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Stanley
authors.forename: John P
authors.initials: JP
authors.lastname: Newnham
authors.forename: Martha
authors.initials: M
authors.lastname: Hickey
mesh_terms: D000418:Albumins / Q000378:metabolism; D000735:Androstenedione / Q000032:analysis* / Q000378:metabolism; D000886:Anthropometry; D003687:Dehydroepiandrosterone / Q000032:analysis* / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D000418:Albumins; D000735:Androstenedione; D003687:Dehydroepiandrosterone