title: Risk factors for obstetric morbidity in patients with uterine atony undergoing caesarean delivery.
abstract: BACKGROUND
  Uterine atony (UA) is recognized as a leading cause of postpartum haemorrhage. However, knowledge of risk factors of haemorrhage-related morbidity among patients diagnosed with UA is uncertain. We investigated risk factors for haemorrhage-related morbidity among patients undergoing Caesarean delivery with UA.
  
  
  METHODS
  We conducted a secondary analysis of data sourced from a 4-yr observational study at 19 US academic centres. Patients with UA were identified based on receiving methylergonovine or carboprost. Our primary outcome (haemorrhage-related morbidity) included a composite of intra- or postpartum transfusion; Caesarean hysterectomy; uterine or hypogastric artery ligation; intensive care admission for: pulmonary oedema, coagulopathy, adult respiratory distress syndrome, postoperative ventilation, or invasive line monitoring.
  
  
  RESULTS
  Among 57,182 patients who underwent Caesarean delivery, 2294 (4%) patients developed UA. Haemorrhage-related morbidity occurred in 450 (19.6%) patients with UA. The risk of haemorrhage-related morbidity was increased among African-Americans [adjusted odds ratio (aOR)=2.36; 95% confidence interval (CI)=1.73-3.23], Hispanics (aOR=1.4; 95% CI=1.04-1.9), women with multiple gestations (aOR=1.59; 95% CI=1.06-2.38), placenta praevia (aOR=4.89; 95% CI=3.04-7.87), patients with ASA class III (aOR=1.4; 95 CI=1.03-1.9), or ASA class IV (aOR=5.88; 95% CI=2.48-13.9), exposure to general anaesthesia (GA) (aOR=2.4; 95% CI=1.59-3.62) and combined general and regional anaesthesia (aOR=4.0; 95% CI=2.62-6.09), and ≥2 prior Caesarean deliveries (aOR=1.62; 95% CI=1.1-2.39).
  
  
  CONCLUSIONS
  Among patients with UA undergoing Caesarean delivery, the risk of haemorrhage-related morbidity is increased in African-Americans, Hispanics, patients with multiple gestations, placenta praevia, ASA class III or IV, ≥2 prior Caesarean deliveries and those undergoing GA.
authors.affiliation: Department of Anaesthesia and ajbut@stanford.edu.
authors.forename: A J
authors.initials: AJ
authors.lastname: Butwick
authors.affiliation: Department of Anaesthesia and.
authors.forename: B
authors.initials: B
authors.lastname: Carvalho
authors.affiliation: Department of Obstetrics and Gynaecology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Y Y
authors.initials: YY
authors.lastname: El-Sayed
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000773:Anesthesia, Obstetrical; D015992:Body Mass Index; D002260:Carboprost / Q000494:pharmacology; D002585:Cesarean Section / Q000009:adverse effects / Q000379:methods*; D036861:Delivery, Obstetric / Q000009:adverse effects*; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008755:Methylergonovine / Q000494:pharmacology; D010120:Oxytocics / Q000494:pharmacology; D010923:Placenta Previa / Q000453:epidemiology; D006473:Postpartum Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D015203:Reproducibility of Results; D012307:Risk Factors; D012959:Socioeconomic Factors; D014593:Uterine Inertia / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D010120:Oxytocics; D002260:Carboprost; D008755:Methylergonovine
keywords: Caesarean section; morbidity; uterine atony