title: Neurodevelopmental outcome over time of preterm born children ≤750 g at birth.
abstract: BACKGROUND
  Extremely low birth weight (ELBW) infants are at risk of cognitive impairment and follow-up is therefore of major importance. The age at which their neurodevelopmental outcome (NDO) can reliably be predicted differs in the literature.
  
  
  OBJECTIVE
  To describe NDO at 2, 3.5 and 5.5 years in an ELBW cohort. To examine the value of NDO at 2 years corrected age (CA) for prediction of NDO at 3.5 and 5.5 years.
  
  
  METHODS
  A retrospective cross-sectional and longitudinal cohort study.
  
  
  METHODS
  101 children with a BW≤750 g, born between 1996 and 2005, who survived NICU admission and were included in a follow-up program.
  
  
  METHODS
  NDO, measured with different tests for general development and intelligence, depending on age of assessment and classified as normal (Z-score≥-1), mildly delayed (-2≤Z-score<-1) or severely delayed (Z-score<-2).
  
  
  RESULTS
  At 2, 3.5 and 5.5 years 74.3, 82.2 and 76.2% had a normal NDO. A normal NDO at 2 years CA predicted a normal NDO at 3.5 and 5.5 years in 92% and 84% respectively. Of the children with a mildly or severely delayed NDO at 2 years CA the majority showed an improved NDO at 3.5 (69.2%) and 5.5 years (65.4%) respectively.
  
  
  CONCLUSIONS
  The majority of the children with a BW≤750 g had a normal NDO at all ages. A normal NDO at 2 years CA is a good predictor for normal outcome at 3.5 and 5.5 years, whereas a delayed NDO at 2 years CA is subject to change with the majority of the children showing a better NDO at 3.5 and 5.5 years.
authors.affiliation: Department of Obstetrics, University Medical Centre, Wilhelmina Children's Hospital, Utrecht, The Netherlands. m.j.claas@umcutrecht.nl
authors.forename: M J
authors.initials: MJ
authors.lastname: Claas
authors.forename: L S
authors.initials: LS
authors.lastname: de Vries
authors.forename: H W
authors.initials: HW
authors.lastname: Bruinse
authors.forename: I C
authors.initials: IC
authors.lastname: van Haastert
authors.forename: M M A
authors.initials: MM
authors.lastname: Uniken Venema
authors.forename: L M
authors.initials: LM
authors.lastname: Peelen
authors.forename: C
authors.initials: C
authors.lastname: Koopman
mesh_terms: D016009:Chi-Square Distribution; D002657:Child Development / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D002658:Developmental Disabilities / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight / Q000502:physiology* / Q000523:psychology; D008137:Longitudinal Studies; D011237:Predictive Value of Tests; D011247:Pregnancy