Automated conduction velocity analysis in the electrohysterogram for prediction of imminent delivery: a preliminary study.

BACKGROUND: Analysis of the electrohysterogram (EHG) is a promising diagnostic tool for preterm delivery. For the introduction in the clinical practice, analysis of the EHG should be reliable and automated to guarantee reproducibility. STUDY GOAL: Investigating the feasibility of automated analysis of the EHG conduction velocity (CV) for detecting imminent delivery. MATERIALS AND METHODS: Twenty-two patients presenting with uterine contractions (7 preterm) were included. An EHG was obtained noninvasively using a 64-channel high-density electrode grid. Contractions were selected based on the estimated intrauterine pressure derived from the EHG, the tocodynamometer, and maternal perception. Within the selected contractions, the CV vector was identified in two dimensions. RESULTS: Nine patients delivered within 24 hours and were classified as a labor group. 64 contractions were analyzed; the average amplitude of the CV vector was significantly higher for the labor group, 8.65 cm/s ± 1.90, compared to the nonlabor group, 5.30 cm/s ± 1.47 (P < 0.01). CONCLUSION: The amplitude of the CV is a promising parameter for predicting imminent (preterm) delivery. Automated estimation of this parameter from the EHG signal is feasible and should be regarded as an important prerequisite for future clinical studies and applications.

Vectorial analysis of the electrohysterogram for prediction of preterm delivery: a preliminary study.

Electrophysiological measurement of uterine contractions, referred to as electrohysterogram (EHG), is potentially more informative than methods currently used during pregnancy for timely recognition of complications such as preterm labor. Unfortunately, EHG measurement and interpretation remain challenging. Recently, some attention has been dedicated to the analysis of the EHG propagation, which is hypothetically predictive of the delivery time. This hypothesis, though physiologically reasonable, has not been investigated yet. A dedicated maximum likelihood (ML) method has been proposed and validated for identifying the conduction velocity vector of single EHG spikes. This validated ML method is here employed for comparing the conduction velocity vector in two groups of pregnant women with uterine contractions that were prospectively classified as productive or unproductive contractions. The estimated conduction velocity vector showed significant differences in the two groups. The spikes extracted from those contractions eventually classified as unproductive showed a significantly lower conduction velocity amplitude (CV = 4.89 ± 1.19 cm.s(-1) vs CV = 8.63 ± 2.92 cm.s(-1)) and a higher occurrence of upward propagation relative to productive contractions. These results suggest that productive and unproductive uterine contractions are associated to significantly different properties of the conduction velocity vector, which is likely to be proven fundamental in predicting preterm delivery.