Toward a new modality for detecting a uterine rupture: electrohysterogram propagation analysis during trial of labor after cesarean

Objective: Observational cohort study which aimed to explore the potential of electrohysterogram (EHG) analysis for detecting a uterine rupture during trial of labor after cesarean. The EHG propagation characteristics surrounding the uterine scar of six patients with a previous cesarean section were compared to a control group of five patients without a scarred uterus.
Methods: The EHG was recorded during the first stage of labor using a high-resolution 64- channel electrode grid positioned on the maternal abdomen across the cesarean scar. Based on simulations, the inter-channel correlation and propagation direction were adopted as EHG parameters for evaluating possible disruption of electrical propagation by the uterine scar.
Results: No significant differences in inter-channel correlation or propagation direction were observed between the group of patients with an intact uterine scar and the control group. A strong predominance of vertical propagation was observed in one case, in which scar rupture occurred.
Conclusions: The results support unaffected propagation of electrical activity through the intact uterine scar tissue suggesting that changes in the EHG might only occur in case of rupture.