title: Investigation of an increase in postpartum haemorrhage in Canada.
abstract: OBJECTIVE
  To investigate the cause of a recent increase in hysterectomies for postpartum haemorrhage in Canada.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Canada between 1991 and 2004.
  
  
  METHODS
  All hospital deliveries in Canada as documented in the database of the Canadian Institute for Health Information (excluding incomplete data from Quebec, Manitoba and Nova Scotia).
  
  
  METHODS
  Deliveries with postpartum haemorrhage by subtype were identified using International Classification of Diseases codes, while hysterectomies were identified using procedure codes. Changes in determinants of postpartum haemorrhage (all postpartum haemorrhage and that requiring hysterectomy) were examined, and crude and adjusted period changes were assessed using logistic models.
  
  
  METHODS
  Postpartum haemorrhage, postpartum haemorrhage with hysterectomy, postpartum haemorrhage with blood transfusion and postpartum haemorrhage by subtype.
  
  
  RESULTS
  Rates of postpartum haemorrhage increased from 4.1% in 1991 to 5.1% in 2004 (23% increase, 95% CI 20-26%), while rates of postpartum haemorrhage with hysterectomy increased from 24.0 in 1991 to 41.7 per 100,000 deliveries in 2004 (73% increase, 95% CI 27-137%). These increases were because of an increase in atonic postpartum haemorrhage, from 29.4 per 1000 deliveries in 1991 to 39.5 per 1000 deliveries in 2004 (34% increase, 95% CI 31-38%). Adjustment for temporal changes in risk factors did not explain the increase in atonic postpartum haemorrhage but attenuated the increase in atonic postpartum haemorrhage with hysterectomy.
  
  
  CONCLUSIONS
  There has been a recent, unexplained increase in the frequency, and possibly the severity, of atonic postpartum haemorrhage in Canada.
authors.affiliation: Department of Obstetrics and Gynaecology, Dalhousie University, Halifax, Canada. ksjoseph@dal.ca
authors.forename: K S
authors.initials: KS
authors.lastname: Joseph
authors.forename: J
authors.initials: J
authors.lastname: Rouleau
authors.forename: M S
authors.initials: MS
authors.lastname: Kramer
authors.forename: D C
authors.initials: DC
authors.lastname: Young
authors.forename: R M
authors.initials: RM
authors.lastname: Liston
authors.forename: T F
authors.initials: TF
authors.lastname: Baskett
mesh_terms: D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007044:Hysterectomy / Q000706:statistics & numerical data; D015994:Incidence; D006473:Postpartum Hemorrhage / Q000453:epidemiology* / Q000601:surgery; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors