title: Evaluation of selection criteria for validating paired umbilical cord blood gas samples: an observational study.
abstract: OBJECTIVE
  To compare six validation criteria for umbilical cord blood gas (UCBG) values in vigorous and nonvigorous neonates.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Single tertiary obstetric centre, King Edward Memorial Hospital (KEMH), Perth, Western Australia.
  
  
  METHODS
  A total of 37,763 consecutive deliveries at >23 weeks of gestation.
  
  
  METHODS
  Six validation criteria were compared to evaluate the proportion of deliveries with 'valid' UCBG data; and the proportion of vigorous and nonvigorous neonates with metabolic acidaemia.
  
  
  RESULTS
  Proportion of deliveries with 'valid' UCBG values; proportions of vigorous and nonvigorous neonates with normal, borderline and abnormal UCBG values.
  
  
  RESULTS
  The criteria based on KEMH 5th centile arteriovenous pH and Pco(2) differences resulted in a higher proportion of neonates with 'valid' UCBG values than the previously described Westgate and Kro criteria. The increase in 'valid' UCBG values occurred across the entire study population including vigorous and nonvigorous neonates. Among neonates with short-term neonatal complications there was an increase in nonvigorous neonates with umbilical artery metabolic acidaemia. There was no corresponding increase in vigorous neonates diagnosed with abnormal UCBG values.
  
  
  CONCLUSIONS
  Use of the KEMH criteria results in an increase in the proportion of nonvigorous term neonates with UCBG data considered 'valid' to aid clinicians in the management of the neonate shortly after delivery. This change occurs without increasing the rate of false-positive diagnoses of acidaemia in vigorous neonates. The KEMH 'validation' criteria were developed from an entire presenting population and provide a simple algorithm that can be universally applied to identify neonates with nonphysiological UCBG values.
authors.affiliation: School of Women's and Infants' Health, The University of Western Australia, Perth, Australia.
authors.forename: C R H
authors.initials: CR
authors.lastname: White
authors.forename: D A
authors.initials: DA
authors.lastname: Doherty
authors.forename: R
authors.initials: R
authors.lastname: Kohan
authors.forename: J P
authors.initials: JP
authors.lastname: Newnham
authors.forename: C E
authors.initials: CE
authors.lastname: Pennell
mesh_terms: D000138:Acidosis / Q000097:blood / Q000175:diagnosis*; D000465:Algorithms; D001034:Apgar Score; D001784:Blood Gas Analysis; D015331:Cohort Studies; D003661:Decision Support Techniques; D005312:Fetal Blood / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014469:Umbilical Arteries; D014471:Umbilical Veins