title: Reduced prevalence of metabolic acidosis at birth: an analysis of established STAN usage in the total population of deliveries in a Swedish district hospital.
abstract: OBJECTIVE
  The purpose of this study was to investigate quality-of-care improvements after the introduction of ST waveform analysis as an adjunct to standard cardiotocography (CTG).
  
  
  METHODS
  This was a prospective clinical study that was conducted over 7 years. Four yearly cohorts of 12,832 term pregnancies were part of a detailed analysis. Cord blood metabolic acidosis and neonatal outcome were main outcome measures.
  
  
  RESULTS
  The STAN (S31 Fetal Heart Monitor; Neoventa Medical AB, Mölndal, Sweden) usage rate increased from 26 to 69%. The cord metabolic acidosis rate was reduced from 0.72 to 0.06%. This 91.7% improvement was associated with a significant reduction in the number of cases with a prolonged response time, calculated as the time from CTG + ST indications to intervene until delivery and an ability of the staff to identify and act on preterminal and unstable fetal heart rate patterns at the onset of a recording.
  
  
  CONCLUSIONS
  Our data indicate a paradigm shift in the outcome of delivery related to a high rate of CTG + ST usage and the application of structured CTG analysis.
authors.affiliation: Department of Obstetrics, Sahlgren's University Hospital, Mölndal, Sweden. hakan.noren@vgregion.se
authors.forename: Håkan
authors.initials: H
authors.lastname: Norén
authors.forename: Ann
authors.initials: A
authors.lastname: Carlsson
mesh_terms: D000138:Acidosis / Q000097:blood / Q000453:epidemiology*; D015148:Cardiotocography / Q000379:methods*; D036861:Delivery, Obstetric / Q000379:methods; D005260:Female; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D007743:Labor, Obstetric / Q000097:blood*; D008297:Male; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D013548:Sweden