371: Non-invasive Uterine Monitoring: Comparison of Electrical Uterine Myography (EUM) and Tocodynamometry (TOCO) among Obese Parturients

Abstract

To validate the accuracy of an external device which monitors uterine electrical activity by comparing it to tocodynamometry among obese patients. This was a prospective observational study of laboring women at Montefiore Medical Center from February 2017 to April 2018. Inclusion criteria: maternal age >18 years old, singleton pregnancy, gestational age > 24 weeks and BMI >/= 30 kg/m2. Exclusion criteria: allergy to silver, implanted electronic device of any kind and irritated skin or open wound on the abdominal wall. Patients were monitored simultaneously with the EUM device, EUM300 (OB Tools, Migdal HaEmek, Israel), and by TOCO for at least 30 minutes. Two blinded obstetricians reviewed the tracings. The primary outcome of the study was continuous, interpretable tracing and secondary outcomes were total number of contractions, timing of onset of contractions and duration of contractions. Based on McNemar’s test to compare proportion of discontinuity between the two methods, enrolling 55 patients provided 80% study power to detect an odds ratio of 3.2 with a two-sided type I error rate of 5%. A total of 65 obese patients were monitored via simultaneous EUM and TOCO devices. The average gestational age was 39.0 weeks with 43 (66.15%) patients in latent labor. 35 (53.85%) patients were receiving oxytocin at the time of the recordings and 45 (69.3%) patients had epidural. On average, the EUM was 1.49 minutes (CI= 0.62, 2.37) more interpretable/continuous in a 30 min tracing (p=0.001). Overall, EUM detected 39% (CI= 23%, 57%) more contractions in a 30 min tracing compared to TOCO (p<0.0001). With regards to patient preference, 42 (64.62%) patients undergoing simultaneous monitoring preferred the EUM device over the TOCO. Given the challenges of using a tocodynomameter with obese women, consideration should be given to replacing it with the EUM device, which appears to be more sensitive and accurate and preferred by patients.