title: Smoking in Pregnancy and Child ADHD.
abstract: OBJECTIVE
  There is a well-documented association between maternal smoking during pregnancy and offspring attention-deficit/hyperactivity disorder (ADHD). The degree to which this reflects causal intrauterine effects or is due to unmeasured confounding is not clear. We sought to compare the association between maternal smoking during pregnancy and offspring ADHD with the associations with paternal smoking, grandmother's smoking when pregnant with mother, and maternal smoking in previous pregnancies. Each of these exposures is expected to be influenced by much of the same confounding factors as maternal smoking during pregnancy, but cannot have direct intrauterine effects. A sibling control design was also used.
  
  
  METHODS
  The current study used data from the Norwegian Mother and Child Cohort Study (n > 100 000 children). Mothers and fathers reported on smoking during pregnancy, and mothers reported on smoking in previous pregnancies and their mother's smoking when pregnant with them. Mothers reported on child ADHD symptoms at 5 years of age. Information about child ADHD diagnosis was obtained from the Norwegian Patient Registry.
  
  
  RESULTS
  Maternal smoking during pregnancy was not more strongly associated with offspring ADHD diagnosis than was paternal smoking, grandmother's smoking when pregnant with mother, or maternal smoking in previous pregnancies. Sibling control analyses showed no association between maternal smoking in pregnancy and child ADHD symptoms among siblings discordant for maternal smoking.
  
  
  CONCLUSIONS
  These results suggest that the association between maternal smoking during pregnancy and offspring ADHD is not due to causal intrauterine effects, but reflects unmeasured confounding.
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway; kristinbrun.gustavson@fhi.no.|Department of Psychology, and.
authors.forename: Kristin
authors.initials: K
authors.lastname: Gustavson
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.|Department of Psychology, and.
authors.forename: Eivind
authors.initials: E
authors.lastname: Ystrom
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.|Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Stoltenberg
authors.affiliation: Mailman School of Public Health, Columbia University, New York, New York.|New York State Psychiatric Institute, New York, New York.
authors.forename: Ezra
authors.initials: E
authors.lastname: Susser
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Pål
authors.initials: P
authors.lastname: Surén
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Gun Peggy
authors.initials: GP
authors.lastname: Knudsen
authors.affiliation: The MRC Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom.
authors.forename: George Davey
authors.initials: GD
authors.lastname: Smith
authors.affiliation: School of Psychology, and.|MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, United Kingdom; and.
authors.forename: Kate
authors.initials: K
authors.lastname: Langley
authors.affiliation: Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Rutter
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Heidi
authors.initials: H
authors.lastname: Aase
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Ted
authors.initials: T
authors.lastname: Reichborn-Kjennerud
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009664:Norway; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology / Q000209:etiology*; D012042:Registries; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D013223:Statistics as Topic; D014028:Tobacco Smoke Pollution / Q000009:adverse effects / Q000706:statistics & numerical data
chemical_list: D014028:Tobacco Smoke Pollution