title: Mediators of the association between pre-eclampsia and cerebral palsy: population based cohort study.
abstract: OBJECTIVE
  To test the hypothesis that pre-eclampsia is a risk factor for cerebral palsy mediated through preterm birth and being born small for gestational age.
  
  
  METHODS
  Population based cohort study.
  
  
  METHODS
  Clinical data from the Norwegian Cerebral Palsy Registry were linked with perinatal data prospectively recorded by the Medical Birth Registry of Norway.
  
  
  METHODS
  All singleton babies who survived the neonatal period during 1996-2006 (849 children with cerebral palsy and 616,658 control children).
  
  
  METHODS
  Cerebral palsy and cerebral palsy subtypes.
  
  
  RESULTS
  Children exposed to pre-eclampsia had an excess risk of cerebral palsy (unadjusted odds ratio 2.5, 95% confidence interval 2.0 to 3.2) compared with unexposed children. Among children born at term (≥ 37 weeks), exposure to pre-eclampsia was not associated with an excess risk of cerebral palsy in babies not born small for gestational age (1.2, 0.7 to 2.0), whereas children exposed to pre-eclampsia and born small for gestational age had a significantly increased risk of cerebral palsy (3.2, 1.5 to 6.7). Non-small for gestational age babies born very preterm (<32 weeks) and exposed to pre-eclampsia had a reduced risk of cerebral palsy compared with unexposed children born at the same gestational age (0.5, 0.3 to 0.8), although the risk was not statistically significantly reduced among children exposed to pre-eclampsia and born small for gestational age (0.7, 0.4 to 1.3). Exposure to pre-eclampsia was not associated with a specific cerebral palsy subtype.
  
  
  CONCLUSIONS
  Exposure to pre-eclampsia was associated with an increased risk of cerebral palsy, and this association was mediated through the children being born preterm or small for gestational age, or both. Among children born at term, pre-eclampsia was a risk factor for cerebral palsy only when the children were small for gestational age.
authors.affiliation: Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, NTNU, PO Box 8905, MTFS, N-7491 Trondheim, Norway. krist@stud.ntnu.no
authors.forename: Kristin Melheim
authors.initials: KM
authors.lastname: Strand
authors.forename: Runa
authors.initials: R
authors.lastname: Heimstad
authors.forename: Ann-Charlotte
authors.initials: AC
authors.lastname: Iversen
authors.forename: Rigmor
authors.initials: R
authors.lastname: Austgulen
authors.forename: Stian
authors.initials: S
authors.lastname: Lydersen
authors.forename: Guro L
authors.initials: GL
authors.lastname: Andersen
authors.forename: Lorentz M
authors.initials: LM
authors.lastname: Irgens
authors.forename: Torstein
authors.initials: T
authors.lastname: Vik
mesh_terms: D000367:Age Factors; D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000175:diagnosis / Q000453:epidemiology*; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D008297:Male; D009664:Norway / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000175:diagnosis / Q000453:epidemiology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011379:Prognosis; D012016:Reference Values; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D015996:Survival Rate