title: Coffee consumption during pregnancy and the risk of hyperkinetic disorder and ADHD: a prospective cohort study.
abstract: OBJECTIVE
  Based on hypotheses from experimental studies, we studied the association between intrauterine exposure to coffee and the risk of clinically verified hyperkinetic disorder and attention-deficit hyperactivity disorder (ADHD).
  
  
  METHODS
  A cohort study with prospectively collected data from the Aarhus Birth Cohort, Denmark. We included 24 068 singletons delivered between 1990 and 1998. Linkage was performed with three Danish longitudinal registers: The Danish Psychiatric Central Register, The Integrated Database for Labour Market Research and The Danish Civil Registration System. We identified 88 children with hyperkinetic disorder and ADHD. Information about coffee consumption during pregnancy was obtained at 16 weeks of gestation from self-administrated questionnaires. Potential confounding factors were evaluated using Cox regression analyses.
  
  
  RESULTS
  We found that intrauterine exposure to 10 or more cups of coffee per day was associated with a threefold increased risk of hyperkinetic disorder and ADHD. After adjustments for a number of confounding factors, the risk decreased and became statistically insignificant (RR 2.3, 95% CI 0.9-5.9).
  
  
  CONCLUSIONS
  Prenatal exposure to high levels of coffee did not significantly increase the risk of clinically verified hyperkinetic disorder and ADHD in childhood.
authors.affiliation: Perinatal Epidemiology Research Unit, Departments of Obstetrics and Paediatrics, Aarhus University Hospital, Skejby, Denmark. kmlinnet@ki.au.dk
authors.forename: Karen Markussen
authors.initials: KM
authors.lastname: Linnet
authors.forename: Kirsten
authors.initials: K
authors.lastname: Wisborg
authors.forename: Niels Jørgen
authors.initials: NJ
authors.lastname: Secher
authors.forename: Per Hove
authors.initials: PH
authors.lastname: Thomsen
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
authors.forename: Søren
authors.initials: S
authors.lastname: Dalsgaard
authors.forename: Tine Brink
authors.initials: TB
authors.lastname: Henriksen