title: Preterm Birth and Poor Fetal Growth  as Risk Factors of Attention-Deficit/  Hyperactivity Disorder.
abstract: BACKGROUND
  Previous studies have shown an association between prematurity and attention- abstract deficit/hyperactivity disorder (ADHD). Results concerning late preterm infants are controversial, and studies examining fetal growth represented by weight for gestational age are scarce. Our objective was to examine the association between gestational age by each week of fetal maturity, weight for gestational age, and ADHD.
  
  
  METHODS
  In this population-based study, 10 321 patients with ADHD, diagnosed according to the International Classification of Diseases and 38 355 controls individually matched for gender, date and place of birth, were identified from Finnish nationwide registers. Perinatal data were obtained from the Finnish Medical Birth Register. Conditional logistic regression was used to examine the association between gestational age, weight for gestational age, and ADHD after controlling for confounding factors.
  
  
  RESULTS
  The risk of ADHD increased by each declining week of gestation. The associations were robust after adjusting for confounders. An elevated risk also was seen among late preterm and early term infants. As for fetal growth, the odds ratio showed a U-shaped curve with an increased risk seen when the weight for gestational age was 1 SD below and 2 SD above the mean.
  
  
  CONCLUSIONS
  Our findings suggest that each gestational week has significance for child's subsequent neurodevelopment and risk for ADHD. We also showed that poor fetal growth increased the risk of ADHD. This highlights the importance of taking into account both prematurity and poor fetal growth when planning the timing of birth as well as later follow-up and support policies.
authors: Minna
authors: M
authors: Sucksdorff
authors: Liisa
authors: L
authors: Lehtonen
authors: Roshan
authors: R
authors: Chudal
authors: Auli
authors: A
authors: Suominen
authors: Petteri
authors: P
authors: Joelsson
authors: Mika
authors: M
authors: Gissler
authors: Andre
authors: A
authors: Sourander
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005387:Finland / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000523:psychology; D008297:Male; D011159:Population Surveillance / Q000379:methods; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D012042:Registries; D012307:Risk Factors; D055815:Young Adult