370: Non-invasive Uterine Monitoring: Comparison of Electrical Uterine Myography (EUM) and Intrauterine Pressure Catheter (IUPC)

Abstract

To validate the accuracy and clinical usefulness of the EUM device by comparing it with simultaneous use of IUPC among laboring 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. Exclusion criteria: allergy to silver, implanted electronic device and irritated skin/open wound on the abdominal wall. Patients were monitored simultaneously with the EUM device, EUM300 (OB Tools, Migdal HaEmek, Israel), and by IUPC 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, 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% power to detect an odds ratio of 3.2 with a two-sided type I error rate of 5%. A total of 68 patients were monitored for 2,749 minutes via simultaneous EUM and IUPC devices: 55 (80.8%) patients were obese. 56 (82.35%) of the patients were receiving oxytocin at the time of the recordings and 67 (98.5%) had epidurals. On average, the EUM was no different with regards to interpretability/continuity when compared to IUPC on a 30-minute tracing (Effect estimate 0.95 (CI= -0.18, 2.08) p=0.10). This finding was similar among obese and nonobese women [Effect estimate 0.50 (CI=0.19, 1.19) p=0.16 and Effect estimate 2.85 (CI= -2.16, 7.85) p=0.27, respectively]. Overall, EUM was no different in its ability to detect contractions among obese and non-obese patients [Effect estimate 1.06 (CI= .99, 1.13) p=0.11 and Effect estimate 1.12 (CI=0.95, 1.33) p=0.17, respectively]. 84% of the patients preferred the EUM device over the IUPC. We were unable to demonstrate a difference between when EUM and IUPC monitoring with regards to interpretability and contraction frequency regardless of maternal obesity. Given that the EUM device is noninvasive and can also monitor contraction strength, future noninferiority studies should be conducted to determine if the EUM device can replace IUPC monitoring.