Spatiotemporal electrohysterography patterns in normal and arrested labor.

OBJECTIVE The purpose of this study was to investigate the spatiotemporal patterns of uterine electrical activity in normal and arrested labors. STUDY DESIGN From a database of electrohysterograms, 12 subjects who underwent cesarean delivery for active-phase arrest were each matched with 2 vaginally delivered controls. Using 30-minute segments of the electrohysterogram during the arrest, or the same dilation in controls, the center of uterine electrical activity was derived. The vertical motion of this center of uterine activity was determined for each contraction and the frequencies of movement patterns analyzed. RESULTS Predominantly upward movement of the center of uterine activity (longer and/or stronger contraction at the fundus) was more common with normal dilation (P = .003). Receiver operating characteristic curve analysis gave an area under the curve of 0.91 for predicting outcome (vaginal vs cesarean delivery). CONCLUSION There is a significant correlation between upward movement of the center of uterine activity (fundal dominance) and current labor progress.