title: Intrauterine effects of maternal prepregnancy overweight on child cognition and behavior in 2 cohorts.
abstract: OBJECTIVE
  Greater maternal prepregnancy adiposity has been associated with behavioral problems, such as attention-deficit/hyperactivity disorder, and lower intellectual function in offspring. However, few studies of humans have explored this, and it is unclear if intrauterine mechanisms or confounding factors drive these associations.
  
  
  METHODS
  Parental adiposity and offspring verbal skills, nonverbal skills, and behavioral problems were assessed in the British Avon Longitudinal Study of Parents and Children (N = ∼5000) and Dutch Generation R (N = ∼2500) cohorts. We aimed to determine the plausibility of intrauterine effects by (1) adjusting for multiple confounders, (2) comparing associations between maternal and paternal overweight with offspring cognition/behaviors, and (3) searching for cross-cohort consistency.
  
  
  RESULTS
  Maternal prepregnancy overweight was associated with reduced child verbal skills (unadjusted). However, after adjusting for confounders, this result was not consistently observed in both cohorts. Maternal overweight was also associated with child total behavior problems and externalizing problems even after adjusting for confounders. However, this was observed in Generation R only and was not replicated in the British Avon Longitudinal Study of Parents and Children. No associations of maternal overweight with child attention problems, emotional/internalizing problems, or nonverbal skills were observed in either cohort. Paternal overweight was not associated with any of the child outcomes but was also less strongly related to potential confounding factors than was maternal overweight.
  
  
  CONCLUSIONS
  Overall, we found little consistent evidence of intrauterine effects of maternal prepregnancy overweight on child cognition and behavior. Some associations initially observed were not consistently replicated across cohorts or robust to adjustment for confounding factors and, thus, are likely to reflect confounding by socioeconomic or postnatal factors.
authors.affiliation: MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, United Kingdom. marie-jo.brion@bristol.ac.uk
authors.forename: Marie-Jo
authors.initials: MJ
authors.lastname: Brion
authors.forename: Mijke
authors.initials: M
authors.lastname: Zeegers
authors.forename: Vincent
authors.initials: V
authors.lastname: Jaddoe
authors.forename: Frank
authors.initials: F
authors.lastname: Verhulst
authors.forename: Henning
authors.initials: H
authors.lastname: Tiemeier
authors.forename: Debbie A
authors.initials: DA
authors.lastname: Lawlor
authors.forename: George Davey
authors.initials: GD
authors.lastname: Smith
mesh_terms: D002652:Child Behavior; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D006801:Humans; D009035:Mothers; D050177:Overweight; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects