title: Prenatal stress and cerebral palsy: a nationwide cohort study in Denmark.
abstract: OBJECTIVE
  Exposure to prenatal stress may affect neurodevelopment of the fetus, but whether this exposure increases the risk of cerebral palsy (CP) later in life is unknown. We aimed to examine the association between maternal bereavement during the prenatal time period and CP in childhood.
  
  
  METHODS
  We conducted a nationwide cohort study by linking information from nationwide registers. All 1,501,894 singletons born in Denmark from 1979 to 2004 were followed up from birth to the end of 2006. We identified 39,601 children whose mothers lost a close relative (child, spouse, parent, sibling) during pregnancy or up to 1 year before pregnancy and they were classified as the exposed group. The outcome of interest was the diagnosis of CP as registered in the National Hospital Register. We used Cox Regression to estimate the hazard ratios (HRs).
  
  
  RESULTS
  Exposure to maternal bereavement after the loss of a child during the prenatal period was associated with an increased risk of CP among children born preterm without intrauterine growth retardation (HR 2.26, 95% CI, 1.09-3.79) and among children born at term with intrauterine growth retardation (HR 2.01, 95% CI, 1.04-3.89). Prenatal stress after maternal bereavement by loss of other relatives was not associated with an increased risk of CP.
  
  
  CONCLUSIONS
  Our data suggest that extremely severe stress in prenatal life could increase the susceptibility for CP among children born preterm or with impaired fetal growth.
authors.affiliation: Department of Epidemiology, Institute of Public Health, The Danish Epidemiology Science Centre, The University of Aarhus, Denmark. jl@soci.au.dk
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
authors.forename: Mogens
authors.initials: M
authors.lastname: Vestergaard
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
authors.forename: Dorthe Hansen
authors.initials: DH
authors.lastname: Precht
authors.forename: Jakob
authors.initials: J
authors.lastname: Christensen
authors.forename: Michael
authors.initials: M
authors.lastname: Lu
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
mesh_terms: D000293:Adolescent; D000328:Adult; D001601:Bereavement; D002547:Cerebral Palsy / Q000453:epidemiology*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005190:Family; D005260:Female; D005315:Fetal Diseases / Q000453:epidemiology*; D005317:Fetal Growth Retardation / Q000453:epidemiology / Q000523:psychology; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000523:psychology; D008297:Male; D018811:Maternal Exposure; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000523:psychology; D011297:Prenatal Exposure Delayed Effects; D012042:Registries; D012307:Risk Factors; D013315:Stress, Psychological / Q000453:epidemiology* / Q000523:psychology