title: Risks for peroperative excessive blood loss in cesarean delivery.
abstract: OBJECTIVE
  To analyze risk factors for peroperative excessive blood loss at cesarean delivery.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Twenty-four of 26 maternity units in Norway with at least 500 expected deliveries per year.
  
  
  METHODS
  A total of 2,778 women having singleton deliveries and participating in the Norwegian Breakthrough Project on Cesarean Section.
  
  
  METHODS
  Elective and emergency operations were analyzed separately with extensive blood loss defined as hemorrhage > 1000 ml with controls defined as bleeding < 500 ml. All analyzes were done in SPSS (version 16.0) with chi-squared tests and logistic regression.
  
  
  METHODS
  Adjusted odds ratios (aOR) of extensive peroperative bleeding.
  
  
  RESULTS
  The prevalence of excessive blood loss differed between women undergoing elective (2.1%) and emergency cesarean deliveries (3.3%). Among maternal factors, chronic maternal diseases, pregnancy and delivery related conditions, placenta previa (aOR 19.7; 95% CI 5.4-72.2) and transverse lie (aOR 4.9; 95% CI 0.9-26.5) were the only risk factors for extensive blood loss in elective operations, whereas placenta previa (aOR 8.4; 95% CI 2.4-29.9), placental abruption (aOR 2.0; 95% CI 2.0-14.5), intervention at full cervical dilation (aOR 3.2; 95% CI 1.4-7.1) and high BMI (aOR 3.4; 95% CI 1.6-7.2) were risks in emergency operations.
  
  
  CONCLUSIONS
  The different risk pattern for excessive bleeding in cesarean deliveries should be recognized when planning available obstetric competence for surgery.
authors.affiliation: Department of Obstetrics and Gynecology, Innlandet Hospital Trust, Lillehammer, Norway. toril.kolas@sykehuset-innlandet.no
authors.forename: Toril
authors.initials: T
authors.lastname: Kolås
authors.forename: Pål
authors.initials: P
authors.lastname: Øian
authors.forename: Finn Egil
authors.initials: FE
authors.lastname: Skjeldestad
mesh_terms: D000293:Adolescent; D000328:Adult; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data*; D016022:Case-Control Studies; D002585:Cesarean Section / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data*; D016009:Chi-Square Distribution; D016001:Confidence Intervals; D017558:Elective Surgical Procedures; D004638:Emergency Treatment; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D007744:Obstetric Labor Complications / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D016017:Odds Ratio; D019990:Perioperative Care; D006473:Postpartum Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D015995:Prevalence; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index