title: Foetal testosterone and autistic traits in 18 to 24-month-old children.
abstract: BACKGROUND
  Autism spectrum conditions have been characterised as an extreme presentation of certain male-typical psychological traits. In addition, several studies have established a link between prenatal exposure to testosterone and cognitive sex differences in later life, and one study found that foetal testosterone (FT) is positively correlated to autistic traits in 6 to 10 year-old children. In this study, we tested whether FT is positively correlated with autistic traits in toddlers aged 18-24 months.
  
  
  METHODS
  Levels of FT were analysed in amniotic fluid and compared with autistic traits, measured using the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in 129 typically developing toddlers aged between 18 and 24 months (mean +/- SD 19.25 +/- 1.52 months).
  
  
  RESULTS
  Sex differences were observed in Q-CHAT scores, with boys scoring significantly higher (indicating more autistic traits) than girls. In addition, we confirmed a significant positive relationship between FT levels and autistic traits.
  
  
  CONCLUSIONS
  The current findings in children between 18 and 24 months of age are consistent with observations in older children showing a positive association between elevated FT levels and autistic traits. Given that sex steroid-related gene variations are associated with autistic traits in adults, this new finding suggests that the brain basis of autistic traits may reflect individual differences in prenatal androgens and androgen-related genes. The consistency of findings in early childhood, later childhood and adulthood suggests that this is a robust association.
authors.affiliation: Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18B Trumpington Rd, Cambridge, CB2 8AH, UK. ba251@cam.ac.uk.
authors.forename: Bonnie
authors.initials: B
authors.lastname: Auyeung
authors.forename: Kevin
authors.initials: K
authors.lastname: Taylor
authors.forename: Gerald
authors.initials: G
authors.lastname: Hackett
authors.forename: Simon
authors.initials: S
authors.lastname: Baron-Cohen