title: [The association of gestational duration and birth weight with child IQ: The Generation R Study].
abstract: BACKGROUND
  Several psychiatric disorders are considered to be neurodevelopmental in origin. Population-based research provides us with a unique opportunity to explore how prenatal factors influence neurodevelopment.
  
  
  OBJECTIVE
  To analyse whether non-verbal child iq is linked to gestational duration and birth weight and to find out whether these birth factors can be seen as to reflect the intra-uterine environment.
  
  
  METHODS
  Participants were 5,893 (73.6%) children enrolled in the Generation R Study. The gestational duration was determined on the basis of foetal ultrasound scans. Birth weight was measured and transformed into standard deviation scores corrected for gestational duration and gender. The non-verbal iq was measured when the child reached the age of six.
  
  
  RESULTS
  Even during in the a-term period, gestational duration showed a linear association with non-verbal iq, whereas the association between birth weight and non-verbal iq was found to be curvilinear.
  
  
  CONCLUSIONS
  Independently and showing different patterns, both gestational duration and birth weight were found to have a predictive value for childhood non-verbal iq. This finding illustrates the various mechanisms that could lead to neurodevelopmental disorders.
authors.forename: N H
authors.initials: NH
authors.lastname: Grootendorst-van Mil
authors.forename: F C
authors.initials: FC
authors.lastname: Verhulst
authors.forename: H
authors.initials: H
authors.lastname: Tiemeier
mesh_terms: D001724:Birth Weight; D002675:Child, Preschool; D056348:Emotional Intelligence; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence / Q000502:physiology*; D065886:Neurodevelopmental Disorders / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D011594:Psychometrics