The fetal ECG: accuracy of measurements

Analysis of fetal heart rate is very dependent upon the accuracy with which fetal events can be timed. This depends upon signal quality and the type of processing used in signal analysis. Signal quality is affected by mode of recording and positioning of sensors. Signal loss can be kept to below 5% in routine clinical practice with appropriate attention to technique. Accuracy of beat-to-beat measurement needs to be 1 ms if short-term variability (epoch length 1/16 min) is to be assessed reliably.