Assessment and quantification of foetal electrocardiography and heart rate variability of normal foetuses from early to late gestational periods

Abstract

Foetal ECG (fECG) during pregnancy was longitudinally assessed from 18 to 41 weeks of gestation in 100 healthy foetuses using a non-invasive fECG monitor with abdominal electrodes. Foetal cardiac time intervals including durations of P wave, PR interval, QRS complex, QT interval, QTc and T wave were evaluated in relation to gestational age and gender to establish normal values and trends. Heart rate variability (HRV) was derived from fECG by performing spectral analysis of the R-R intervals using an experimental algorithm. Analysis of HRV allowed an indirect assessment of the normal development and maturation of the foetal cardiac autonomic nervous system with gestational age. Furthermore, the experimental algorithm was compared with a commercial system for determination of HRV. This study showed the clinical application of non-invasive fECG monitoring, provided insight into the pattern of normative fECG cardiac time intervals and development of foetal cardiac autonomic nervous system with gestational stages.