title: Change in heart rate variability in relation to a significant ST-event associates with newborn metabolic acidosis.
abstract: OBJECTIVE
  To find whether low-to-high frequency (LF/HF) ratio of fetal heart rate (FHR) variability changes in relation to a significant ST-event during delivery, and if the change is predictive of metabolic acidosis of the newborn.
  
  
  METHODS
  A case-control study.
  
  
  METHODS
  Data from a multicentre project.
  
  
  METHODS
  Acidotic and control fetuses with abnormal cardiotocography together with a ST-event in fetal electrocardiogram (ECG).
  
  
  METHODS
  We studied intrapartum FHR variability with spectral analysis from 34 fetuses with a significant ST-event in the fetal ECG. LF/HF ratio of FHR variability was measured within a period of 1 hour before and 1 hour after a significant ST-event. Sensitivity and specificity of the change in LF/HF ratio of FHR variability in prediction of metabolic acidosis (pH < or = 7.05 and base deficit value > 12.0 mmol/l) of the newborn were described by means of the receiver operating characteristic curve.
  
  
  METHODS
  Change in LF/HF ratio of FHR in relation to a significant ST-event.
  
  
  RESULTS
  We found that a relative change in LF/HF ratio greater than 30% in relation to a significant ST-event predicted cord arterial metabolic acidosis with a sensitivity of 89% (95% CI 68-100%) and specificity of 80% (95% CI 64-96%).
  
  
  CONCLUSIONS
  Relative changes in LF/HF ratio of FHR variability in relation to a significant ST-event are more pronounced in fetuses born with metabolic acidosis.
authors.affiliation: Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland. saila.siira@fimnet.fi
authors.forename: S
authors.initials: S
authors.lastname: Siira
authors.forename: T
authors.initials: T
authors.lastname: Ojala
authors.forename: E
authors.initials: E
authors.lastname: Ekholm
authors.forename: T
authors.initials: T
authors.lastname: Vahlberg
authors.forename: S
authors.initials: S
authors.lastname: Blad
authors.forename: K G
authors.initials: KG
authors.lastname: Rosén
mesh_terms: D000138:Acidosis / Q000175:diagnosis* / Q000503:physiopathology; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology; D015148:Cardiotocography; D016022:Case-Control Studies; D004562:Electrocardiography; D005315:Fetal Diseases / Q000175:diagnosis* / Q000503:physiopathology; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn