title: Oxytocin and dystocia as risk factors for adverse birth outcomes: a cohort of low-risk nulliparous women.
abstract: OBJECTIVE
  augmented and not augmented women without dystocia were compared to investigate associations between oxytocin and adverse birth outcomes. Augmented women with and without dystocia were compared, to investigate associations between dystocia and adverse birth outcomes.
  
  
  METHODS
  a cohort of low-risk nulliparous women originally included in a randomised controlled trial.
  
  
  METHODS
  the Department of Obstetrics and Gynaecology, Østfold Hospital Trust, Norway.
  
  
  METHODS
  the study population consists of 747 well defined low-risk women.
  
  
  METHODS
  incidence of oxytocin augmentation, and associations between dystocia and augmentation, and mode of delivery, transfer of newborns to the intensive care unit, episiotomy and postpartum haemorrhage.
  
  
  RESULTS
  of all participants 327 (43.8%) were augmented with oxytocin of which 139 (42.5%) did not fulfil the criteria for dystocia. Analyses adjusted for possible confounders found that women without dystocia had an increased risk of instrumental vaginal birth (OR 3.73, CI 1.93-7.21) and episiotomy (OR 2.47, CI 1.38-4.39) if augmented with oxytocin. Augmented women had longer active phase if vaginally delivered and longer labours if delivered by caesarean section if having dystocia. Among women without dystocia, those augmented had higher body mass index, gave birth to heavier babies, had longer labours if vaginally delivered and had epidural analgesia more often compared to women not augmented.
  
  
  CONCLUSIONS
  in low-risk nulliparous without dystocia, we found an association between the use of oxytocin and an increased risk of instrumental vaginal birth and episiotomy.
  
  
  CONCLUSIONS
  careful attention should be paid to criteria for labour progression and guidelines for oxytocin augmentation to avoid unnecessary use.
authors.affiliation: Department of Obstetrics and Gynaecology, Østfold Hospital Trust, PO Box 24, 1603 Fredrikstad, Norway. Electronic address: stiber@so-hf.no.
authors.forename: Stine
authors.initials: S
authors.lastname: Bernitz
authors.affiliation: Department of Obstetrics and Gynaecology, University Hospital of North Norway, Tromsø, Norway; Women's Health and Perinatology Research Group, Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway.
authors.forename: Pål
authors.initials: P
authors.lastname: Øian
authors.affiliation: Department of Obstetrics and Gynaecology, Vestre Viken Hospital Trust, Drammen, Norway.
authors.forename: Rune
authors.initials: R
authors.lastname: Rolland
authors.affiliation: Unit of Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway.
authors.forename: Leiv
authors.initials: L
authors.lastname: Sandvik
authors.affiliation: Women's Health and Perinatology Research Group, Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway; Clinical Research Department, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Ellen
authors.initials: E
authors.lastname: Blix
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004420:Dystocia / Q000188:drug therapy; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D009664:Norway; D007744:Obstetric Labor Complications / Q000209:etiology*; D010121:Oxytocin / Q000008:administration & dosage / Q000009:adverse effects*; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D012307:Risk Factors
chemical_list: D010121:Oxytocin
keywords: Augmentation; Dystocia; Low-risk birth; Oxytocin