title: Lack of value of routine postpartum hematocrit determination after vaginal delivery.
abstract: OBJECTIVE
  To identify risk factors associated with low postpartum hematocrits after vaginal delivery and to define lower risk categories of patients for whom routine determination of hematocrit may not be necessary.
  
  
  METHODS
  This case-control study was designed to identify risk factors for discharge hematocrit below 27% in nonanemic patients after a vaginal delivery using the University of California, San Francisco, Perinatal Database. Multivariate statistics were used to determine the most significant risk factors. Lower risk subpopulations were analyzed to determine their rate of low discharge hematocrits.
  
  
  RESULTS
  Risk factors associated with odds ratios greater than 1.5 for discharge hematocrit less than 27% included estimated blood loss greater than 500 mL, placenta previa, abruption, prolonged third stage, preeclampsia, prior postpartum hemorrhage, and prior cesarean delivery. Estimated blood loss > 500 mL was the most significant risk factor for discharge hematocrit less than 27% (odds ratio 4.5, 95% confidence interval 3.8, 5.4). A population without statistically significant risk factors was identified; this group had a 1.4% risk of discharge hematocrit less than 27%.
  
  
  CONCLUSIONS
  Routine postpartum hematocrits are unnecessary in clinically stable patients with an estimated blood loss of less than 500 mL.
authors.affiliation: Department of Obstetrics, Gynecology, University of California, San Francisco, USA.
authors.forename: B
authors.initials: B
authors.lastname: Nicol
authors.forename: M
authors.initials: M
authors.lastname: Croughan-Minihane
authors.forename: S J
authors.initials: SJ
authors.lastname: Kilpatrick
mesh_terms: D000293:Adolescent; D000328:Adult; D000740:Anemia / Q000097:blood* / Q000453:epidemiology; D016022:Case-Control Studies; D003955:Diagnostic Tests, Routine; D005069:Evaluation Studies as Topic; D005260:Female; D006400:Hematocrit; D006801:Humans; D016015:Logistic Models; D011181:Postnatal Care; D012307:Risk Factors