© 1998 by European Society of Cardiology
Copyright © 1998, European Society of Cardiology
An estimate of fetal autonomic state by spectral analysis of human umbilical artery flow velocity waveforms
aDepartment of Obstetrics and Gynecology, Academic Hospital Rotterdam — Dijkzigt, Erasmus University, Dr. Molewaterplein 40, 3015 GD Rotterdam, Netherlands
bDepartment of Mechanical Engineering, Rochester Institute of Technology, Rochester, NY, USA
cInstitute of Epidemiology and Biostatistics, Erasmus University, Rotterdam, Netherlands
dSCOR in Pediatric Cardiovascular Diseases, Division of Pediatric Cardiology, University of Rochester Medical Center, Rochester, NY, USA
* Corresponding author. Tel. (+31-10) 463 3632; Fax (+31-10) 463 5826.
Objective: Determination of gestational age-related fluctuations in heart rate in the umbilical artery of the early human fetus. Methods: Doppler velocity recordings from human umbilical artery were obtained, in a cross-sectional study design in 137 singleton pregnancies at 10–20 weeks of gestation. After exclusion criteria were applied, data on 117 normal pregnancies were available and subdivided into group I: 10–12 weeks (n=49); group II: 13–16 weeks (n=43); and group III: 17–20 weeks (n=25). Blood flow velocity waveforms were reconstructed from Doppler audio signals. Variability in heart rate was calculated using Fast Fourier Transforms (FFT). Individual heart rate variability power spectra were subdivided into frequency bands. Results: Fetal heart rate variability decreases at 10–20 weeks and demonstrates a shift to lower frequencies at 17–20 weeks. Conclusions: Fetal heart rate variability is related to gestational age and shows a shift to lower frequencies which may reflect autonomic functional development.
KEYWORDS Umbilical artery velocimetry; Human; Fetal heart rate; Autonomic nervous system