title: A whole-of-population study of term and post-term gestational age at birth and children's development.
abstract: OBJECTIVE
  To examine the risk of poor child development according to week of gestation at birth, among children born ≥ 37 weeks' gestation.
  
  
  METHODS
  Population-based study using linked data (n = 12,601).
  
  
  METHODS
  South Australia.
  
  
  METHODS
  All births ≥ 37 weeks' gestation.
  
  
  METHODS
  Relative risks of developmental vulnerability for each week of gestation were calculated with adjustment for confounders and addressing missing information.
  
  
  METHODS
  Child development was documented by teachers during a national census of children attending their first year of school in 2009, using the Australian Early Development Index (AEDI). Children scoring in the lowest 10% of the AEDI were categorised as developmentally vulnerable.
  
  
  RESULTS
  The percentage of children vulnerable on one or more AEDI domains for the following gestational ages 37, 38, 39, 40, 41, 42-45 weeks was 24.8, 22.3, 20.6, 20.0, 20.4 and 24.2, respectively. Compared with children born at 40 weeks, the adjusted relative risks [(95% confidence interval (CI)] for vulnerability on ≥ 1 AEDI domain were; 37 weeks 1.13 (0.99-1.28), 38 weeks 1.05 (0.96-1.15), 39 weeks 1.02 (0.94-1.12), 41 weeks 1.00 (0.90-1.11) and 42-45 weeks 1.20 (0.84-1.72).
  
  
  CONCLUSIONS
  Children born at 40-41 weeks' gestation may have the lowest risk of developmental vulnerability at school entry, reinforcing the importance of term birth in perinatal care. Early term or post-term gestational age at birth can help clinicians, teachers and parents recognise children with potential developmental vulnerabilities at school entry.
authors.affiliation: School of Population Health, University of Adelaide, Adelaide, SA, Australia.
authors.forename: L G
authors.initials: LG
authors.lastname: Smithers
authors.affiliation: School of Population Health, University of Adelaide, Adelaide, SA, Australia.
authors.forename: A K
authors.initials: AK
authors.lastname: Searle
authors.affiliation: School of Population Health, University of Adelaide, Adelaide, SA, Australia.
authors.forename: C R
authors.initials: CR
authors.lastname: Chittleborough
authors.affiliation: Pregnancy Outcome Unit, South Australian Department for Health and Ageing, Adelaide, SA, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Scheil
authors.affiliation: Fraser Mustard Centre, Telethon Institute for Child Health Research, University of Western Australia, Adelaide, SA, Australia.
authors.forename: S A
authors.initials: SA
authors.lastname: Brinkman
authors.affiliation: School of Population Health, University of Adelaide, Adelaide, SA, Australia.|School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: J W
authors.initials: JW
authors.lastname: Lynch
mesh_terms: D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003625:Data Collection; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D013021:South Australia; D047929:Term Birth
keywords: Child development gestational age