title: The effect of placental isolation on umbilical artery blood gas measurements.
abstract: OBJECTIVE
  We conducted a study to determine whether the pH and base excess of umbilical artery blood samples are significantly different when taken from a double-clamped segment of umbilical cord as compared with a nonisolated segment of umbilical cord.
  
  
  METHODS
  A prospective study with 43 singleton pregnancies was conducted. Matched pair samples of umbilical arterial blood were compared from double-clamped and nonisolated segments. The means for pH and base excess were compared and a paired t test was used to determine significance.
  
  
  RESULTS
  The means for pH and base excess were not significantly different (P = .70) between the 2 groups.
  
  
  CONCLUSIONS
  Double clamping the umbilical cord before obtaining an umbilical artery sample is not necessary for accurate blood gas results.
authors.affiliation: Department of Obstetrics and Gynaecology, Rockyview Hospital, University of Calgary, Calgary, Alberta, Canada. dr.wynneleung@gmail.com
authors.forename: Wynne I
authors.initials: WI
authors.lastname: Leung
authors.forename: Charlene A
authors.initials: CA
authors.lastname: Lyndon
mesh_terms: D000136:Acid-Base Equilibrium; D001784:Blood Gas Analysis; D003250:Constriction; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011247:Pregnancy; D011446:Prospective Studies; D014469:Umbilical Arteries