Computation of short-term fetal heart-rate variability from heart-rate waveforms

Fetal heart-rate monitoring during labor is now routine in high-risk pregnancies. Beat-to-beat, or short-term variability in the heart rate has aroused considerable recent attention and several quantitative indices based on the fetal electrocardiogram have been proposed. These cannot be implemented on micro- or mini- computer-based labor-room systems without additional hardware because of the ECG processing involved. This paper describes a procedure for computing short-term variability from heart-rate waveforms. It correlates excellently with the above methods, but can be implemented on a microcomputer without special interfacing, since it uses only the slowly-varying heart-rate waveform.