title: Obstetric risk factors for early-onset schizophrenia in a Finnish birth cohort.
abstract: OBJECTIVE
  Although case-control investigations have shown an association between obstetric complications and schizophrenia, particularly among patients with early onsets, cohort studies have mostly failed to confirm this effect. The authors examined whether a history of fetal hypoxia and other obstetric complications elevated risk for early-onset schizophrenia in a 1955 Helsinki birth cohort.
  
  
  METHODS
  The subjects were 80 randomly selected patients with schizophrenia (36 with early and 44 with later onsets) representative of all available probands in the cohort, 61 of their nonschizophrenic siblings, and 56 demographically matched nonpsychiatric comparison subjects. Psychiatric diagnoses were obtained from structured clinical interviews, and obstetric data were taken from standardized, prospectively ascertained obstetric records. A score for hypoxia-associated obstetric complications was entered into logistic regression models, along with measures of prenatal infection and fetal growth retardation.
  
  
  RESULTS
  Hypoxia-associated obstetric complications significantly increased the odds of early-onset schizophrenia but not of later-onset schizophrenia or unaffected sibling status, after prenatal infection and fetal growth retardation were taken into account.
  
  
  CONCLUSIONS
  These findings support an association between obstetric complications and increased risk for early-onset schizophrenia. The authors advance a model whereby the neurotoxic effects of fetal hypoxia may lead to an early onset of schizophrenia due to premature cortical synaptic pruning.
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, USA.
authors.forename: I M
authors.initials: IM
authors.lastname: Rosso
authors.forename: T D
authors.initials: TD
authors.lastname: Cannon
authors.forename: T
authors.initials: T
authors.lastname: Huttunen
authors.forename: M O
authors.initials: MO
authors.lastname: Huttunen
authors.forename: J
authors.initials: J
authors.lastname: Lönnqvist
authors.forename: T L
authors.initials: TL
authors.lastname: Gasperoni
mesh_terms: D000328:Adult; D017668:Age of Onset; D001238:Asphyxia Neonatorum / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D005190:Family; D005260:Female; D005315:Fetal Diseases / Q000453:epidemiology* / Q000235:genetics; D005317:Fetal Growth Retardation / Q000453:epidemiology; D005311:Fetal Hypoxia / Q000453:epidemiology; D005387:Finland / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology* / Q000235:genetics