Breathing modulates fetal heart rate

To assess the modulation of fetal heart rate (FHR) by breathing movements, the authors investigated the relationship between FHR and fetal breathing rate (FBR). FHR was obtained from the R-R interval of the EKG and FBR from the burst-burst interval of the diaphragmatic electromyogram (EMG). The R-R intervals of EKG and burst-burst interval of the diaphragmatic EMG were determined using a template recognition method. These data were then analyzed in both the frequency and time domains. Frequency analysis was carried out using the linear prediction method with the optimum order. It is confirmed that fetal breathing movements modulate fetal heart-rate variability.<
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