title: Fetal growth and behaviour problems in early adolescence: findings from the Mater University Study of Pregnancy.
abstract: BACKGROUND
  The nature of the association between birth weight and behavioural problems in adolescence is unclear. Recent studies are limited by their capacity to adjust for important obstetric and measurement issues. Aim To examine the nature of the association between birth weight and a range of behavioural symptoms, including anxiety/depression and social problems, in adolescence.
  
  
  METHODS
  Data from 4971 mothers and their children participating in the Mater University Study of Pregnancy (MUSP), a prospective, population-based birth cohort, are presented. This study commenced in Brisbane, Australia, in 1981. Mothers and their children were followed up at 3-5 days post-birth, and 6 months, 5 years and 14 years after the initial interview. Internalizing and externalizing behaviour problems, social problems and anxiety/depressive symptoms were assessed using Achenbach's Youth Self Report (YSR) of the Child Behaviour Check List (CBCL).
  
  
  RESULTS
  There was no evidence of a linear association between birth weight and behavioural symptoms, when birth weight z-scores were examined as a continuous variable. However, a non-linear association was identified when birth weight z-scores were categorized into quintiles. Children in the lowest and highest quintiles were at higher risk of increased anxiety/depressive and social problems symptoms. After adjustment for potential confounders, birth weight showed a non-linear association with the log odds of social problems {Quintile 1 odds ratio (OR) 1.59 [95% confidence interval (CI) 1.13, 2.23] Quintile 5 OR 1.57 (95% CI 1.12, 2.20)}.
  
  
  CONCLUSIONS
  Our findings provide further support for an association between birth weight and some adolescent behaviour problems. This association is likely to be non-linear, affecting babies at both the lower and higher ends of the birth weight distribution.
authors.affiliation: School of Population Health, University of Queensland, Brisbane, Australia. r.alati@sph.uq.edu.au
authors.forename: Rosa
authors.initials: R
authors.lastname: Alati
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Najman
authors.forename: Michael
authors.initials: M
authors.lastname: O'Callaghan
authors.forename: William
authors.initials: W
authors.lastname: Bor
authors.forename: Gail M
authors.initials: GM
authors.lastname: Williams
authors.forename: Alexandra
authors.initials: A
authors.lastname: Clavarino
mesh_terms: D000293:Adolescent; D001724:Birth Weight / Q000502:physiology*; D002653:Child Behavior Disorders / Q000453:epidemiology* / Q000523:psychology; D002675:Child, Preschool; D003866:Depressive Disorder / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D011793:Queensland / Q000453:epidemiology; D012917:Social Adjustment; D011795:Surveys and Questionnaires