Fetal heart-rate variability response to uterine contractions during labour and delivery

Using cardiotocography data from labour and delivery, the objective of this study was to decompose fetal-heart rate variability (fHRV) based on auto-regressive power spectral density analysis into a quiescent component unrelated to contraction and a peak component response to contraction. During the last 3 hours of labour and delivery, this approach discriminated between normal and pathological fetuses in 15 of 18 epochs for the movement frequency (MF, 150-500 mHz) peak component and 11 of 18 epochs for the low frequency (LF, 30-150 mHz) peak component, and in all epochs of the quiescent components. These results were superior to previous results based on a longer time window that did not differentiate between contraction and non-contraction intervals. They are also very promising for the improved detection of fetal distress related to hypoxia.