title: Cerebral cortical thickness and a history of obstetric complications in schizophrenia.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) studies have demonstrated that patients with schizophrenia have thinner brain cortices compared with healthy control subjects. Neurodevelopment is vulnerable to obstetric complications (OCs) such as hypoxia and birth trauma, factors that are also related to increased risk of developing schizophrenia. With the hypothesis that OCs might explain the thinner cortices found in schizophrenia, we studied patients with schizophrenia and healthy controls subjects for association between number and severity of OCs and variation in cortical thickness.
  
  
  METHODS
  MRI scans of 54 adults with schizophrenia or schizoaffective disorder and 54 healthy controls were acquired at Karolinska Institutet, Stockholm, Sweden. Measures of brain cortical thickness were obtained using automated computer processing (FreeSurfer). OCs were assessed from obstetric records and scored blindly according to the McNeil-Sjöström scale. At numerous cortical locations, putative effects of OCs on cortical thickness variation were tested for each trimester, for labour, for composite OC scores, severe OC scores, and hypoxia scores among patients and controls separately.
  
  
  RESULTS
  Number and severity of OCs varied among both patient and control subjects but were not associated with cortical thickness in either of the groups. Patients demonstrated thinner brain cortices but there were no significant differences in number and severity of OC scores across groups.
  
  
  CONCLUSIONS
  In the present study, number and severity of obstetric complications were not associated with brain cortical thickness, in patients with schizophrenia or in healthy control subjects. The thinner brain cortices found in patients with schizophrenia were not explained by a history of OCs.
authors.affiliation: Institute of Psychiatry, University of Oslo, P.O. Box 85 Vinderen, N-0319 Oslo, Norway. unn.haukvik@medisin.uio.no
authors.forename: Unn Kristin
authors.initials: UK
authors.lastname: Haukvik
authors.forename: Glenn
authors.initials: G
authors.lastname: Lawyer
authors.forename: Petr Szulc
authors.initials: PS
authors.lastname: Bjerkan
authors.forename: Cecilie Bhandari
authors.initials: CB
authors.lastname: Hartberg
authors.forename: Erik G
authors.initials: EG
authors.lastname: Jönsson
authors.forename: Thomas
authors.initials: T
authors.lastname: McNeil
authors.forename: Ingrid
authors.initials: I
authors.lastname: Agartz
mesh_terms: D000328:Adult; D001719:Birth Certificates; D001921:Brain / Q000002:abnormalities / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D007744:Obstetric Labor Complications / Q000473:pathology* / Q000503:physiopathology* / Q000523:psychology; D011247:Pregnancy; D011618:Psychotic Disorders / Q000473:pathology; D012559:Schizophrenia / Q000150:complications* / Q000473:pathology; D012565:Schizophrenic Psychology; D018709:Statistics, Nonparametric