title: Comparison of maternal mortality and morbidity between trial of labor and elective cesarean section among women with previous cesarean delivery.
abstract: OBJECTIVE
  This study was undertaken to assess the safety of trial of labor after previous cesarean delivery.
  
  
  METHODS
  Retrospective cohort study of 308,755 Canadian women with previous cesarean delivery between 1988 and 2000. Occurrences of in-hospital maternal death, uterine rupture, and other severe maternal morbidity were compared between women with a trial of labor and those with an elective cesarean section.
  
  
  RESULTS
  Rates of uterine rupture (0.65%), transfusion (0.19%), and hysterectomy (0.10%) were significantly higher in the trial-of-labor group. Maternal in-hospital death rate, however, was lower in the trial-of-labor group (1.6 per 100,000) than in the elective cesarean section group (5.6 per 100,000). The association between trial of labor and uterine rupture was stronger in low volume (<500) than in high volume (> or =500 births per year) obstetric units.
  
  
  CONCLUSIONS
  Trial of labor is associated with increased risk of uterine rupture, but elective cesarean section may increase the risk of maternal death.
authors.affiliation: Division of Health Surveillance and Epidemiology, Centre for Healthy Human Development, Health Canada, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada. swwen@ohri.ca
authors.forename: Shi Wu
authors.initials: SW
authors.lastname: Wen
authors.forename: I D
authors.initials: ID
authors.lastname: Rusen
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
authors.forename: Robert
authors.initials: R
authors.lastname: Liston
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kramer
authors.forename: Tom
authors.initials: T
authors.lastname: Baskett
authors.forename: Maureen
authors.initials: M
authors.lastname: Heaman
authors.forename: Shiliang
authors.initials: S
authors.lastname: Liu
mesh_terms: D001803:Blood Transfusion / Q000706:statistics & numerical data; D002170:Canada; D002585:Cesarean Section / Q000401:mortality; D017558:Elective Surgical Procedures; D005260:Female; D006764:Hospitals, Community; D006801:Humans; D007044:Hysterectomy / Q000706:statistics & numerical data; D008428:Maternal Mortality; D009017:Morbidity; D011247:Pregnancy; D014219:Trial of Labor; D014597:Uterine Rupture / Q000453:epidemiology