Unmonitored Labor Episodes in Obese Parturients With Wireless Versus Conventional Fetal Heart Rate Monitoring [16S

Abstract

INTRODUCTION: To determine the frequency and duration of unmonitored labor (UL) episodes in obese parturients exposed to wireless fetal heart rate (FHR) monitoring compared to exclusively conventional wired FHR monitoring. METHODS: Retrospective cohort of obese gravidas with non-anomalous, term singleton gestations admitted for induction or early labor at a tertiary hospital. Patients were excluded for initial cervical dilation ≥5 cm or prior cesarean delivery. Groups were defined by whether any exposure to wireless FHR monitoring (Monica Novii Wireless Patch System, GE Healthcare) occurred during admission for delivery. Each subject's complete FHR tracing was reviewed. Outcomes were UL episodes/hour and minutes/hour of FHR monitoring. UL is defined as ≥2 minutes of absent or discontinuous FHR tracing, excluding intentional interruptions exceeding 30 minutes. RESULTS: A total of 1,350 hours of FHR monitoring were reviewed for 52 deliveries (24 wireless, 28 wired). BMI was higher in the wireless compared to the wired group (38.1 vs. 34.7 kg/m2); no other demographic differences were observed. In the wireless group, 54.2% of FHR monitoring time was wireless. No differences in UL were observed between the wireless and wired groups. However, within the wired group, which was exposed to both forms of FHR monitoring, there were fewer UL episodes/hour (0.41 vs. 0.85; P<0.005) and UL minutes/hour (2.8 vs. 7.5; P<0.001) during the wireless FHR monitoring period compared with the wired FHR monitoring period. CONCLUSION: Wireless FHR monitoring may reduce periods of UL, particularly in high BMI patients. Future studies should evaluate whether this affects obstetrical outcomes.