Observations on electrical activity of the pregnant uterus, not in labor

Abstract

1.1. Electrical activity associated with the uterus can be demonstrated in pregnancy prior to labor.2.2. In late pregnancy, from the thirty-fifth week onward, a high level of electrical activity is reached, signaling the approaching onset of labor.3.3. The very great variability and relative lack of pattern may suggest multiple foci and localized events, or sporadic pacemaker activity.4.4. Appearance of major diphasic slow waves probably indicates the conduction and spread of excitation waves.5.5. It appears that, toward the end of gestation, pacemaker activity, conduction of the excitation waves, and muscular response are activated in that order.6.6. From the thirty-fifth week onward, this epoch electrically speaking may have the physiologic function of preparation for the end of gestation by means of favoring activation of pacemaker, conduction, and response, and possibly the establishment of the hegemony of a single pacemaker.