title: Uterine rupture without previous caesarean delivery: a population-based cohort study.
abstract: OBJECTIVE
  To determine incidence and patient characteristics of women with uterine rupture during singleton births at term without a previous caesarean delivery.
  
  
  METHODS
  Population based cohort study. Women with term singleton birth, no record of previous caesarean delivery and planned vaginal delivery (n=611,803) were identified in the Danish Medical Birth Registry (1997-2008). Medical records from women recorded with uterine rupture during labour were reviewed to ascertain events of complete uterine rupture. Relative Risk (RR) and adjusted Relative Risk Ratio (aRR) of complete uterine rupture with 95% confidence intervals (95% CI) were ascertained according to characteristics of the women and of the delivery.
  
  
  RESULTS
  We identified 20 cases with complete uterine rupture. The incidence of complete uterine rupture among women without previous caesarean delivery was about 3.3/100,000 deliveries. Multiparity (RR 8.99 (95% CI 1.86-43.29)), induction of labour (RR 3.26 (95% CI 1.24-8.57)), epidural analgesia (RR 10.78 (95% CI 4.25-27.39)), and augmentation by oxytocin (RR 9.50 (95% CI 3.15-28.63)) were associated with uterine rupture. Induction of labour was not significantly related to uterine rupture when adjusted for parity, epidural analgesia and augmentation by oxytocin.
  
  
  CONCLUSIONS
  Although uterine rupture is rare, its association with epidural analgesia and augmentation of labour with oxytocin in multipara should be considered. Thus, vigilance should be exercised when labour is obstructed and there is need for epidural analgesia and/or augmentation by oxytocin in multiparous women. Due to the rare occurrence of uterine rupture caution should be exerted when interpreting the findings of this study.
authors.affiliation: Department of Gynaecology and Obstetrics, University of Copenhagen, Holbaek Hospital, Smedelundsgade 60, 4300 Holbaek, Denmark. Electronic address: thiding@yahoo.dk.
authors.forename: Dorthe L A
authors.initials: DLA
authors.lastname: Thisted
authors.affiliation: Section of Social Medicine, University of Copenhagen, Oester Farimagsgade 5, 1014 Copenhagen, Denmark.
authors.forename: Laust H
authors.initials: LH
authors.lastname: Mortensen
authors.affiliation: Department of Gynaecology and Obstetrics, University of Copenhagen, Holbaek Hospital, Smedelundsgade 60, 4300 Holbaek, Denmark.
authors.forename: Lone
authors.initials: L
authors.lastname: Krebs
mesh_terms: D000328:Adult; D015360:Analgesia, Epidural / Q000706:statistics & numerical data*; D016362:Analgesia, Obstetrical / Q000706:statistics & numerical data; D002585:Cesarean Section; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007751:Labor, Induced / Q000706:statistics & numerical data*; D010120:Oxytocics; D010121:Oxytocin; D010298:Parity; D011247:Pregnancy; D012042:Registries; D012189:Retrospective Studies; D014597:Uterine Rupture / Q000453:epidemiology*
chemical_list: D010120:Oxytocics; D010121:Oxytocin
keywords: Augmentation of labour; Epidural analgesia; Induced labour; Multiparity; Spontaneous rupture; Uterine rupture