Quantifying Phase Coupling between Fetal Heart Rate and Uterine Contractions

Abstract

Fetal heart rate (FHR) and uterine contractions (UC) are routinely monitored during labor using cardiotocogra-phy (CTG). Clinical interpretation of CTG signals often assesses signal coupling patterns to determine fetal responses to uterine contractions. However, their effectiveness is sometimes limited by low-quality recordings. Traditionally, CTG quality is assessed based on signal loss percentage, overlooking the possibility that non-zero signals may still be non-physiological. This study aims to investigate the coupling relationship between non-zero FHR and UC signals and determine its potential as an index for CTG quality assessment. Using a dataset of 271 CTG recordings without signal d..