Intrapartum signal quality with external fetal heart rate monitoring: a two way trial of external Doppler CTG ultrasound and the abdominal fetal electrocardiogram.
OBJECTIVE
The objective of this study was to assess the fetal heart rate (FHR) signal quality of non-invasive abdominal fetal electrocardiogram (fECG) in comparison to the Doppler ultrasound cardiotocogram (CTG) during the first and second stage of labour.


METHODS
This was a prospective observational study of non-invasive fECG using five abdominally sited electrodes against the traditional Doppler ultrasound CTG probe on 144 patients. Data were analysed for signal quality before and after outlier removal.


RESULTS
Abdominal fECG signal quality was significantly better during the first stage of labour in comparison to Doppler CTG (median fECG reliability of 95.7 % vs. median 87.3 % for Doppler, p < 0.001), whereas during second stage of labour, equivalence was demonstrated (p > 0.05). For the first and second stage of labour, fECG showed 106/135 (78.5 %) and 46/98 (46.9 %) women having fetal signal loss below 20 %, respectively. Similarly, Doppler ultrasound demonstrated 104/135 (77.0 %) and 51/98 (52.0 %) women having fetal signal loss below 20 % during first and second stage of labour, respectively.


CONCLUSIONS
The non-invasive abdominal fECG presents an improved FHR signal quality during the first stage of labour and an equivalent signal quality during the second stage.
Department of Obstetrics and Gynaecology, Faculty of Medicine, Johann Wolfgang Goethe University Frankfurt am Main, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. Joscha.reinhard@kgu.de
Joscha
J
Reinhard
Barrie R
BR
Hayes-Gill
Sven
S
Schiermeier
Wolfgang
W
Hatzmann
Eva
E
Herrmann
Tomas M
TM
Heinrich
Frank
F
Louwen
D000005:Abdomen; D015148:Cardiotocography; D004562:Electrocardiography; D005260:Female; D005323:Fetal Monitoring / Q000379:methods*; D006340:Heart Rate, Fetal; D006801:Humans; D007747:Labor Stage, First; D007748:Labor Stage, Second; D011247:Pregnancy; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D018608:Ultrasonography, Doppler