title: Obstetric risk factors and autism spectrum disorders in Finland.
abstract: OBJECTIVE
  To examine the relationship between obstetric risk factors and childhood autism, Asperger syndrome, and other pervasive developmental disorders (PDDs).
  
  
  METHODS
  Registry-based case-control study from all singleton births in Finland from 1990-2005. Cases with childhood autism, Asperger syndrome, or PDD (n = 4713) were identified from the Finnish Hospital Discharge Register. Each case was matched to 4 controls on sex, date of birth, and place of birth. Information on obstetric risk factors was from the Finnish Medical Birth Register. Conditional logistic regression models were used for statistical analyses.
  
  
  RESULTS
  When adjusted with confounders, childhood autism was associated with maternal high blood pressure (OR 1.49, 95% CI 1.1-2.1, P = .018), Apgar scores less than 7 (1 minute, OR 1.46, 95% CI 1.1-2.0, P = .021), and neonatal treatment with monitoring (OR 1.40, 95% CI 1.02-1.9, P = .038). PDD was associated with induced labor (OR 1.25 95% CI 1.1-1.5, P = .007), planned cesarean delivery (OR 1.34, 95% CI 1.1-1.7, P = .009), 1-minute Apgar scores 7-8 ( OR 1.22, 95% CI 1.1-1.4, P = .008) and less than 7 (OR 1.34, 95% CI 1.03-1.8, P = .032), and neonatal intensive care unit treatment (OR 1.52, 95% CI 1.2-2.0, P = .003). Asperger syndrome was associated only with 1-minute Apgar scores 7-8 (OR 1.19, 95% CI 1.03-1.4, P = .018).
  
  
  CONCLUSIONS
  Low Apgar scores as well as conditions requiring neonatal special follow-up are important risk factors for childhood autism and PDD. These findings suggest that fetal distress is a potential risk factor for these disorders, but not for Asperger syndrome.
authors.affiliation: Department of Obstetrics and Gynecology, University of Turku, Turku, Finland; Department of Obstetrics and Gynecology, Turku University Hospital, Turku, Finland.
authors.forename: Päivi
authors.initials: P
authors.lastname: Polo-Kantola
authors.affiliation: Department of Child Psychiatry, University of Turku, Turku, Finland.
authors.forename: Katja M
authors.initials: KM
authors.lastname: Lampi
authors.affiliation: Department of Child Psychiatry, University of Turku, Turku, Finland.
authors.forename: Susanna
authors.initials: S
authors.lastname: Hinkka-Yli-Salomäki
authors.affiliation: National Institute of Health and Welfare (THL), Helsinki, Finland; Nordic School of Public Health, Gothenburg, Sweden.
authors.forename: Mika
authors.initials: M
authors.lastname: Gissler
authors.affiliation: Department of Psychiatry, New York State Psychiatric Institute, College of Physicians and Surgeons of Columbia University, New York, NY; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Brown
authors.affiliation: Department of Child Psychiatry, University of Turku, Turku, Finland; Department of Child Psychiatry, Turku University Hospital, Turku, Finland. Electronic address: andre.sourander@utu.fi.
authors.forename: Andre
authors.initials: A
authors.lastname: Sourander
mesh_terms: D001034:Apgar Score; D016022:Case-Control Studies; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000453:epidemiology; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology*; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors
keywords: ASD; Autism spectrum disorder; FHDR; FIPS-A; FMBR; Finnish Hospital Discharge Register; Finnish Medical Birth Register; Finnish Prenatal Study of Autism; ICD-10; ICD-9; International Classification of Diseases-10th Revision; International Classification of Diseases-9th Revision; NICU; Neonatal intensive care unit; PAR; PDD; Pervasive developmental disorder; Population attributable risk; SES; SGA; Small for gestational age; Socioeconomic status