191: Uterine electromyography during spontaneous and abnormal labor

to utilize non-invasive transabdominal uterine EMG monitoring via myometrial electrical activity in order to differentiate between spontaneous and abnormal labor. In a prospective double-blind study, electrical uterine myography (EUM) was measured in 63 women in active labor. Patients were classified into spontaneous or abnormal labor (based on Friedman′s labor curve). EUM, pitocin dose, and cervical characteristics were measured for 20 minutes at diagnosis and at two-hour intervals thereafter. The EUM system is comprised of a multi-channel surface electromyogram operative that senses electromyographic activity, a three-dimensional position sensor, and a personal computer. Data were sent for analysis offsite to an individual blinded to the clinical data. Sixty-three patients participated in the study (37 with abnormal labor and 26 controls). The study revealed: (1) during longitudinal analysis of patients with labor abnormalities in active phase, the electrical uterine activity increased after the administration of pitocin (480.9 ± 122 vs. 580.9 ± 123; p=0.0008); (2) the uterine electrical activity increased during active phase in spontaneous laboring patients (RMS1: 464.5 ± 112; RMS2: 509.1 ± 121 RMS3: 532.8 ± 118.7, p=0.04); (3) analysis of the electrical uterine activity of patients in spontaneous labor vs. those receiving pitocin augmentation was non significant (509.1 ± 121 vs. 513.8 ± 117; 532.8 ± 118 vs. 551.3 ± 114, respectively); (4) evaluation of the cervix at 6 and 8 cm showed significant increase in the dose of pitocin (7 vs. 10, p value 0.02) with similar electrical uterine activity (RMS 580.9 ± 37.0 vs. 572.5 ± 41.8). Our data suggests comparable electrical uterine activity occurs in both spontaneous and augmented laboring patients. However, our data further suggests that similar uterine activity in these patients can be achieved with lower doses of pitocin.