title: Risk of affective disorders following prenatal exposure to severe life events: a Danish population-based cohort study.
abstract: OBJECTIVE
  To examine the effect of prenatal exposure to severe life events on risk of affective disorders in the offspring.
  
  
  METHODS
  In a cohort of 1.1 million Danish births from May 1978 until December 1997, mothers were considered exposed if one (or more) of their close relatives died or was diagnosed with serious illness up to 6 months before conception or during pregnancy. Offspring were followed up from their 10th birthday until their death, migration, onset of affective disorder or 31 December 2007; hospital admissions were identified by linkage to the Central Psychiatric Register. Log-linear Poisson regression was used for data analysis.
  
  
  RESULTS
  The risk of affective disorders was increased in male offspring whose mothers were exposed to severe life events during the second trimester (adjusted RR 1.55 [95% CI 1.05-2.28]). There was an increased risk of male offspring affective disorders in relation to maternal exposure to death of a relative in the second trimester (adjusted RR 1.74 [95% CI 1.06-2.84]) or serious illness in a relative before pregnancy (adjusted RR 1.44 [95% CI 1.02-2.05]). There was no evidence for an association between prenatal exposure to severe life events and risk of female offspring affective disorders.
  
  
  CONCLUSIONS
  Our population-based study suggests that prenatal maternal exposure to severe life events may increase the risk of affective disorders in male offspring. These findings are consistent with studies of populations exposed to famine and earthquake disasters which indicate that prenatal environment may influence the neurodevelopment of the unborn child.
authors.affiliation: Anu Research Centre, Department of Obstetrics and Gynecology, University College Cork, Cork University Maternity Hospital, Cork, Ireland. a.khashan@ucc.ie
authors.forename: Ali S
authors.initials: AS
authors.lastname: Khashan
authors.forename: Roseanne
authors.initials: R
authors.lastname: McNamee
authors.forename: Tine B
authors.initials: TB
authors.lastname: Henriksen
authors.forename: Marianne G
authors.initials: MG
authors.lastname: Pedersen
authors.forename: Louise C
authors.initials: LC
authors.lastname: Kenny
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Abel
authors.forename: Preben B
authors.initials: PB
authors.lastname: Mortensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003718:Denmark; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000453:epidemiology* / Q000523:psychology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000523:psychology*; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult