title: Obstetric complications and risk of schizophrenia. Effect of gender, age at diagnosis and maternal history of psychosis.
abstract: BACKGROUND
  Obstetric complications have been studied frequently as possible risk factors for schizophrenia.
  
  
  OBJECTIVE
  To test the hypotheses that individual obstetric complications are most strongly associated with an increased risk of schizophrenia in males, in patients with an early age at first diagnosis and in subjects with a maternal history of psychosis.
  
  
  METHODS
  Cases of schizophrenia diagnosed between January 1971 and June 1994 were identified in the Stockholm County In-Patient Register. Controls were matched on age, gender, hospital of birth and parish of birth. Obstetric data were recorded blind to case-control status for 524 cases and 1043 controls.
  
  
  RESULTS
  This study did not find any large or consistent effect of gender, age at diagnosis or maternal history of psychosis on the risk of schizophrenia associated with individual complications.
  
  
  CONCLUSIONS
  Future studies should examine these effects using a much larger sample that includes patients with schizophrenia and control subjects whose genetic risk of schizophrenia has been assessed accurately.
authors.affiliation: Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, Wales, UK. thomashv@cardiff.ac.uk
authors.forename: H V
authors.initials: HV
authors.lastname: Thomas
authors.forename: C
authors.initials: C
authors.lastname: Dalman
authors.forename: A S
authors.initials: AS
authors.lastname: David
authors.forename: J
authors.initials: J
authors.lastname: Gentz
authors.forename: G
authors.initials: G
authors.lastname: Lewis
authors.forename: P
authors.initials: P
authors.lastname: Allebeck
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009035:Mothers; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications; D011618:Psychotic Disorders / Q000453:epidemiology; D012044:Regression Analysis; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000209:etiology*; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology