title: Direct antenatal fetal electrocardiographic waveform analysis.
abstract: OBJECTIVE
  To establish a technique for continuous recording of fetal electrocardiograms (ECG) for waveform analysis in the antenatal period.
  
  
  METHODS
  Prospective descriptive study.
  
  
  METHODS
  Fetal Medicine Unit, Queen Charlotte's and Chelsea Hospital, London, UK.
  
  
  METHODS
  35 women undergoing antenatal fetal blood sampling.
  
  
  METHODS
  One end of an insulated Cooner wire was attached to the sampling needle and the other to an automatic ECG-ST waveform analyser.
  
  
  METHODS
  ECG signals were obtained with the needle in the fetal abdomen during intrahepatic umbilical vein sampling or aspiration of fetal urine but not when it was in the placental cord insertion.
  
  
  RESULTS
  Continuous recording of the T/QRS ratio was obtained for a total of 166 min (mean 8 min per fetus) from 20 fetuses (16-38 weeks). The T/QRS ratio had no correlation with gestational age and fetal heart rate and was similar to values described in term fetuses in labour.
  
  
  CONCLUSIONS
  The technique described can identify ST waveform changes and may be useful in the investigation of fetal cardiac arrhythmias, intrauterine growth retardation and in monitoring fetal transfusions.
authors.affiliation: Royal Postgraduate Medical School, Queen Charlotte's and Chelsea Hospital, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Arulkumaran
authors.forename: U
authors.initials: U
authors.lastname: Nicolini
authors.forename: N M
authors.initials: NM
authors.lastname: Fisk
authors.forename: Y
authors.initials: Y
authors.lastname: Tannirandorn
authors.forename: K G
authors.initials: KG
authors.lastname: Rosen
authors.forename: C H
authors.initials: CH
authors.lastname: Rodeck
mesh_terms: D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis; D005323:Fetal Monitoring / Q000379:methods*; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D011446:Prospective Studies