title: Hypertension in pregnancy and risk of coronary heart disease and stroke: A prospective study in a large UK cohort.
abstract: BACKGROUND
  Many studies investigating long-term vascular disease risk associated with hypertensive pregnancies examined risks in relatively young women among whom vascular disease is uncommon. We examined the prospective relation between a history of hypertension during pregnancy and coronary heart disease (CHD) and stroke in middle-aged UK women.
  
  
  METHODS
  In 1996-2001, 1.1 million parous women (mean age=56years) without vascular disease at baseline reported their history of hypertension during pregnancy and other factors. They were followed for incident CHD and stroke (hospitalisation or death). Adjusted relative risks (RRs) were calculated using Cox regression.
  
  
  RESULTS
  Twenty-six percent (290,008/1.1 million) reported having had a hypertensive pregnancy; 27% (79,163/290,008) of women with hypertensive pregnancy, but only 10% (82,145/815,560) of those without hypertensive pregnancy, reported being treated for hypertension at baseline. Mean follow-up was 11.6years (mean ages at diagnosis/N of events: CHD=65years/N=68,161, ischaemic stroke=67years/N=8365, haemorrhagic stroke=64years/N=5702). Overall, the RRs (95% confidence interval [CI]) of incident disease in women with hypertensive pregnancy versus those without such history were: CHD=1.29 (1.27-1.31), ischaemic stroke=1.29 (1.23-1.35), and haemorrhagic stroke=1.14 (1.07-1.21). However, among women with hypertensive pregnancy who were not taking hypertension treatment at baseline, their RRs (95% CI) were only modestly increased: CHD=1.17 (1.14-1.19), ischaemic stroke=1.18 (1.11-1.25), and haemorrhagic stroke=1.09 (1.02-1.18).
  
  
  CONCLUSIONS
  Hypertension during pregnancy was associated with increased CHD and stroke incidence in middle age, largely because such women also had hypertension in their 50s and 60s, which has a substantially greater effect on vascular disease risk than hypertension during pregnancy without hypertension later in life.
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: dexter.canoy@ceu.ox.ac.uk.
authors.forename: Dexter
authors.initials: D
authors.lastname: Canoy
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: ben.cairns@ceu.ox.ac.uk.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Cairns
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: angela.balkwill@ceu.ox.ac.uk.
authors.forename: Angela
authors.initials: A
authors.lastname: Balkwill
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: lucy.wright@ceu.ox.ac.uk.
authors.forename: F Lucy
authors.initials: FL
authors.lastname: Wright
authors.affiliation: Fetal Medicine Unit, Department of Obstetrics and Gynaecology, St. George's Medical School, University of London, London, UK. Electronic address: akhalil@sgul.ac.uk.
authors.forename: Asma
authors.initials: A
authors.lastname: Khalil
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: pa.valerie.beral@ceu.ox.ac.uk.
authors.forename: Valerie
authors.initials: V
authors.lastname: Beral
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: jane.green@ceu.ox.ac.uk.
authors.forename: Jane
authors.initials: J
authors.lastname: Green
authors.affiliation: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Bldg., Roosevelt Drive, Oxford OX3 7LF, UK. Electronic address: gill.reeves@ceu.ox.ac.uk.
authors.forename: Gillian
authors.initials: G
authors.lastname: Reeves
mesh_terms: D015331:Cohort Studies; D003327:Coronary Disease / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000175:diagnosis / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology*; D006113:United Kingdom / Q000453:epidemiology
keywords: Coronary heart disease; Hypertension; Hypertensive pregnancy; Stroke; Women