title: Severe maternal morbidity in Canada, 1991-2001.
abstract: BACKGROUND
  Although death rates are often used to monitor the quality of health care, in industrialized countries maternal deaths have become rare. Severe maternal morbidity has therefore been proposed as a supplementary indicator for surveillance of the quality of maternity care. Our purpose in this study was to describe severe maternal morbidity in Canada over a 10-year period, among women with or without major pre-existing conditions.
  
  
  METHODS
  We carried out a retrospective cohort study of severe maternal morbidity involving 2,548,824 women who gave birth in Canadian hospitals between 1991 and 2000. Thirteen conditions that may threaten the life of the mother (e.g., eclampsia) and 11 major pre-existing chronic conditions (e.g., diabetes) that could be identified from diagnostic codes were noted.
  
  
  RESULTS
  The overall rate of severe maternal morbidity was 4.38 per 1000 deliveries. The fatality rate among these women was 158 times that of the entire sample. Rates of venous thromboembolism, uterine rupture, adult respiratory distress syndrome, pulmonary edema, myocardial infarction, severe postpartum hemorrhage requiring hysterectomy, and assisted ventilation increased substantially from 1991 to 2000. The presence of major pre-existing conditions increased the risk of severe maternal morbidity to 6-fold.
  
  
  CONCLUSIONS
  Severe maternal morbidity occurs in about 1 of 250 deliveries in Canada, with marked recent increases in certain morbid conditions such as pulmonary edema, myocardial infarction, hemorrhage requiring hysterectomy, and the use of assisted ventilation.
authors.affiliation: OMNI Research Group, Department of Obstetrics and Gynaecology, Ottawa Health Research Institute, University of Ottawa, Ottawa, Ont. swwen@ohri.ca
authors.forename: Shi Wu
authors.initials: SW
authors.lastname: Wen
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: Robert
authors.initials: R
authors.lastname: Liston
authors.forename: Maureen
authors.initials: M
authors.lastname: Heaman
authors.forename: Tom
authors.initials: T
authors.lastname: Baskett
authors.forename: I D
authors.initials: ID
authors.lastname: Rusen
authors.forename: K S
authors.initials: KS
authors.lastname: Joseph
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kramer
mesh_terms: D000328:Adult; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008428:Maternal Mortality / Q000639:trends; D009017:Morbidity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors