Comparative Study of Uterine Myoelectrical Response to Labour Induction Drugs in Nulliparous and Parous Women with Different EHG Analysis Techniques

Induction of labour (IOL) is one of the most widespread practices to promote the onset of labour when maternal-fetal well-being is compromised. Currently, the monitoring of this procedure in clinical practice is performed with subjective and poorly reproducible techniques such as tocography and cervical assessment, without taking into account other obstetric variables of special relevance as parity. Electrohysterography (EHG) has emerged as a promising alternative due to its usefulness and non-invasiveness. Traditionally, EHG has been characterized by analyzing the EHG-bursts (EBA) associated with uterine contractions and computing temporal, spectral and nonlinear parameters. Recent studies characterize the EHG by considering both EHG-burst and basal activity (WEWA). The first objective of this study was to discern which analysis technique presented the best performance for EHG characterization during IOL. Subsequently, differences in uterine myoelectric response to IOL drugs in nulliparous and parous women were analyzed and compared. EHG recordings were performed during the first 4 hours of IOL in 15 nulliparous and 10 parous women. EBA results showed a greater number of parameters with significant differences with their corresponding baseline ones than WEWA, as well as a greater slope in both parity groups. Parous women presented greater amplitude and more pronounced downward trends for nonlinear parameters than nulliparous, especially for Sample and Spectral Entropy, which is associated with a greater predisposition to achieve APL that is corroborated by obstetric variables. Moreover, future efforts seem necessary to study in depth the differences between parity groups in order to correctly characterize and interpret their evolution.