title: The Risk of Gestational Diabetes Mellitus Following Bereavement: A Cohort Study from Denmark and Sweden.
abstract: BACKGROUND
  We investigated whether bereavement of a close family member - a source of severe psychological stress exposure - the year before pregnancy is associated with gestational diabetes mellitus (GDM).
  
  
  METHODS
  We studied pregnant women with livebirths in Denmark during 1994-2008 and with births in Sweden during 1987-2006 (n = 2,569,446). We obtained data on death of women's parents, siblings, and older children, and on demographic and health- and pregnancy-related factors through linkage between nationwide registers.
  
  
  RESULTS
  In multivariable models, death of a close relative the year before pregnancy was associated with a 14% increased odds of GDM [95% confidence intervals (CIs) 1.03, 1.26]. The odds ratios corresponding to the loss of a child, parent, and sibling were 1.51 (95% CI: 1.17, 1.95), 1.12 (95% CI: 1.00, 1.25), and 0.68 (95% CI: 0.40, 1.25), respectively. Deaths due to cardiovascular diseases or diabetes were more closely related to the risk of GDM than other types of deaths. We found no association between unnatural deaths and the risk of GDM.
  
  
  CONCLUSIONS
  Death of a close relative the year before pregnancy was associated with a modestly increased GDM risk. Our findings according to the relative's cause of death suggest that differences in screening for GDM among exposure groups and residual confounding by familial factors related to metabolic and cardiovascular diseases may have contributed to this association. If there is a causal stress effect on GDM in this predominantly Nordic population, it is most likely small.
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden.
authors.forename: Krisztina D
authors.initials: KD
authors.lastname: László
authors.affiliation: Section for Epidemiology, Department of Public Health, Aarhus University, Aarhus, Denmark.|Department of Epidemiology, School of Public Health, University of California, Los Angeles, CA.
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.affiliation: Section for Epidemiology, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden.
authors.forename: Martina
authors.initials: M
authors.lastname: Persson
authors.affiliation: Research Unit for General Practice, Department of Public Health, Aarhus University, Aarhus, Denmark.|Section for General Practice, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Mogens
authors.initials: M
authors.lastname: Vestergaard
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Svensson
authors.affiliation: Research Unit for General Practice, Department of Public Health, Aarhus University, Aarhus, Denmark.|Section for General Practice, Department of Public Health, Aarhus University, Aarhus, Denmark.|Research Program for Mental Child Health, Department of Public Health, Aarhus University and Institute of Handicap and Communication, Aarhus, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden.
authors.forename: Sven
authors.initials: S
authors.lastname: Cnattingius
mesh_terms: D000328:Adult; D001601:Bereavement; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D016640:Diabetes, Gestational / Q000453:epidemiology / Q000209:etiology* / Q000523:psychology; D005190:Family / Q000523:psychology*; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D008016:Life Change Events; D011247:Pregnancy; D012042:Registries; D012307:Risk Factors; D013315:Stress, Psychological / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: bereavement; cohort study; gestational diabetes mellitus; stress