Power spectral analysis of the heart rate variability of goat fetuses during extrauterine incubation.

Our aim is to determine the relationship between heart rate and behavioral states of a fetal goat using power spectral analysis. Electrocardiograms, electrocortical activity, and fetal breathing movements are recorded from 7 goat fetuses during extrauterine incubation. The heart rate power spectrum is classified into very low, low, and high frequency bands, and behavioral states are classified into low-voltage electrocortical activity with fetal breathing movements (LVB), low-voltage electrocortical activity without fetal breathing movements (LVN), and high-voltage electrocortical activity (HVN). There is a significant difference in total power spectral density in the high frequency band between LVN and HVN, and LVN and LVB. The relationship between each fetal behavioral state is assessed by power spectral analysis.