title: Pre-eclampsia and first-onset postpartum psychiatric episodes: a Danish population-based cohort study.
abstract: BACKGROUND
  Recent evidence suggests that postpartum psychiatric episodes may share similar etiological mechanisms with immune-related disorders. Pre-eclampsia is one of the most prevalent immune-related disorders of pregnancy. Multiple clinical features are shared between pre-eclampsia and postpartum psychiatric disorders, most prominently a strong link to first pregnancies. Therefore, we aimed to study if pre-eclampsia is a risk factor for first-onset postpartum psychiatric episodes.
  
  
  METHODS
  We conducted a cohort study using the Danish population registry, with a total of 400 717 primiparous women with a singleton delivery between 1995 and 2011. First-lifetime childbirth was the main exposure variable and the outcome of interest was first-onset postpartum psychiatric episodes. The main outcome measures were monthly incidence rate ratios (IRRs), with the period 11-12 months after birth as the reference category. Adjustments were made for age, calendar period, reproductive history, and perinatal maternal health including somatic and obstetric co-morbidity.
  
  
  RESULTS
  Primiparous women were at particularly high risk of first-onset psychiatric episodes during the first month postpartum [IRR 2.93, 95% confidence interval (CI) 2.53-3.40] and pre-eclampsia added to that risk (IRR 4.21, 95% CI 2.89-6.13). Having both pre-eclampsia and a somatic co-morbidity resulted in the highest risk of psychiatric episodes during the 3-month period after childbirth (IRR 4.81, 95% CI 2.72-8.50).
  
  
  CONCLUSIONS
  We confirmed an association between pre-eclampsia and postpartum psychiatric episodes. The possible explanations for this association, which are not mutually exclusive, include the psychological impact of a serious medical condition such as pre-eclampsia and the neurobiological impact of pre-eclampsia-related vascular pathology and inflammation.
authors.affiliation: National Center for Register-Based Research,Aarhus School of Business and Social Sciences,Aarhus University,Fuglesangs Allé 4,Aarhus,Denmark.
authors.forename: V
authors.initials: V
authors.lastname: Bergink
authors.affiliation: National Center for Register-Based Research,Aarhus School of Business and Social Sciences,Aarhus University,Fuglesangs Allé 4,Aarhus,Denmark.
authors.forename: T M
authors.initials: TM
authors.lastname: Laursen
authors.affiliation: National Center for Register-Based Research,Aarhus School of Business and Social Sciences,Aarhus University,Fuglesangs Allé 4,Aarhus,Denmark.
authors.forename: B M W
authors.initials: BM
authors.lastname: Johannsen
authors.affiliation: Department of Psychiatry, Erasmus Medical Center,'s Gravendijkwal 230,3000 CA,Rotterdam,The Netherlands.
authors.forename: S A
authors.initials: SA
authors.lastname: Kushner
authors.affiliation: Department of Psychiatry,The University of North Carolina at Chapel Hill,Campus Box #7160,Chapel Hill,NC 27599,USA.
authors.forename: S
authors.initials: S
authors.lastname: Meltzer-Brody
authors.affiliation: National Center for Register-Based Research,Aarhus School of Business and Social Sciences,Aarhus University,Fuglesangs Allé 4,Aarhus,Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Munk-Olsen
mesh_terms: D000328:Adult; D001722:Birth Order / Q000523:psychology*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology* / Q000209:etiology*; D049590:Postpartum Period / Q000523:psychology*; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D012042:Registries; D012307:Risk Factors; D055815:Young Adult
keywords: Epidemiology; immunology; postpartum depression; postpartum psychosis; pre-eclampsia