title: Asphyxia-related risk factors and their timing in spastic cerebral palsy.
abstract: OBJECTIVE
  To investigate the association of asphyxia-related conditions (reducing blood flow or blood oxygen levels in the fetus) with spastic cerebral palsy (CP) considering different gestational age groups and the timing of risk.
  
  
  METHODS
  Population-based case-control study.
  
  
  METHODS
  Danish Cerebral Palsy Register in eastern Denmark and Danish Medical Birth Register.
  
  
  METHODS
  271 singletons with spastic CP and 217 singleton controls, frequency matched by gestational age group, born 1982-1990 in eastern Denmark.
  
  
  METHODS
  Data were abstracted from medical records, and a priori asphyxia-related conditions and other risk factors were selected for analysis. Each factor was classified according to the time at which it was likely to first be present.
  
  
  METHODS
  Spastic CP.
  
  
  RESULTS
  Placental and cord complications accounted for the majority of asphyxia conditions. In multivariate analysis, placental infarction was significantly associated with a four-fold increased risk for spastic quadriplegia and cord around the neck was significantly associated with a three-fold increased risk for spastic CP overall. The combination of placental infarction and being small for gestational age (SGA) afforded an especially high risk for spastic quadriplegia. Placental and cord complications were present in 21% of cases and 12% of controls.
  
  
  CONCLUSIONS
  The risk for spastic quadriplegia from placental infarction may be linked in some cases with abnormal fetal growth (17% of all children with spastic quadriplegia and 3% of control children both had an infarction and were SGA) -- suggesting an aetiologic pathway that encompasses both factors. The risk for spastic CP from cord around the neck is not accounted for by other prepartum or intrapartum factors we examined. Considering the relative timing of risk factors provides a useful framework for studies of CP aetiology.
authors.affiliation: NANEA, Department of Epidemiology, Institute of Public Health, University of Aarhus, Aarhus, Denmark. leni@soci.au.dk
authors.forename: L F
authors.initials: LF
authors.lastname: Nielsen
authors.forename: D
authors.initials: D
authors.lastname: Schendel
authors.forename: J
authors.initials: J
authors.lastname: Grove
authors.forename: D
authors.initials: D
authors.lastname: Hvidtjørn
authors.forename: B
authors.initials: B
authors.lastname: Jacobsson
authors.forename: T
authors.initials: T
authors.lastname: Josiassen
authors.forename: M
authors.initials: M
authors.lastname: Vestergaard
authors.forename: P
authors.initials: P
authors.lastname: Uldall
authors.forename: P
authors.initials: P
authors.lastname: Thorsen
mesh_terms: D000293:Adolescent; D000328:Adult; D001238:Asphyxia Neonatorum / Q000209:etiology*; D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000209:etiology*; D003718:Denmark; D005260:Female; D005315:Fetal Diseases; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology; D007744:Obstetric Labor Complications; D010922:Placenta Diseases; D011247:Pregnancy; D011782:Quadriplegia / Q000209:etiology; D012042:Registries; D012307:Risk Factors; D014470:Umbilical Cord; D055815:Young Adult