title: Post-term birth and the risk of behavioural and emotional problems in early childhood.
abstract: BACKGROUND
  Post-term birth, defined as birth after pregnancy duration of 42 weeks, is associated with increased neonatal morbidity and mortality. The long-term consequences of post-term birth are unknown. We assessed the association of post-term birth with problem behaviour in early childhood.
  
  
  METHODS
  The study was performed in a large population-based prospective cohort study in Rotterdam, The Netherlands. Pregnant mothers enrolled between 2001 and 2005. Of a cohort of 5145 children, 382 (7%) were born post-term, and 226 (4%) were born preterm. Parents completed a standardized and validated behavioural checklist (Child Behavior Checklist, CBCL/1.5-5) when their children were 1.5 and 3 years old. We examined the relation between gestational age (GA) at birth, based on early fetal ultrasound examination, and problem behaviour with regression analyses, adjusting for socio-economic and pregnancy-related confounders.
  
  
  RESULTS
  A quadratic relationship between GA at birth and problem behaviour indicates that both preterm and post-term children have higher behavioural and emotional problem scores than the term born children. Compared with term born children, post-term born children had a higher risk for overall problem behaviour [odds ratio (OR) = 2.10, 95% confidence interval (CI) = 1.32-3.36] and were almost two and a half times as likely to have attention deficit / hyperactivity problem behaviour (OR = 2.44, 95% CI = 1.38-4.32).
  
  
  CONCLUSIONS
  Post-term birth was associated with more behavioural and emotional problems in early childhood, especially attention deficit / hyperactivity problem behaviour. When considering expectant management, this aspect of post-term pregnancy should be taken into account.
authors.affiliation: Department of Child and Adolescent Psychiatry, Erasmus MC--Sophia, Rotterdam, The Netherlands. h.marrounel@erasmusmc.nl
authors.forename: Hanan
authors.initials: H
authors.lastname: El Marroun
authors.forename: Mijke
authors.initials: M
authors.lastname: Zeegers
authors.forename: Eric A P
authors.initials: EA
authors.lastname: Steegers
authors.forename: Jan
authors.initials: J
authors.lastname: van der Ende
authors.forename: Jacqueline J
authors.initials: JJ
authors.lastname: Schenk
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Vincent W V
authors.initials: VW
authors.lastname: Jaddoe
authors.forename: Frank C
authors.initials: FC
authors.lastname: Verhulst
authors.forename: Henning
authors.initials: H
authors.lastname: Tiemeier
mesh_terms: D000328:Adult; D000342:Affective Symptoms / Q000453:epidemiology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology; D002653:Child Behavior Disorders / Q000453:epidemiology*; D002675:Child, Preschool; D004644:Emotions; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007233:Infant, Postmature / Q000523:psychology*; D007234:Infant, Premature; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011247:Pregnancy; D011446:Prospective Studies; D012044:Regression Analysis; D018570:Risk Assessment; D012959:Socioeconomic Factors; D016216:Ultrasonography, Prenatal