Performance of a Maternal Abdominal Surface Electrode System for Fetal Heart Rate and Uterine Contraction Monitoring from 34 to 37 Weeks

Abstract

Objective: Compare performance of a maternal surface electrode patch with ultrasound- and tocodynamometer-based monitoring to detect fetal heart rate and uterine contractility in late preterm labors. Study design: Thirty women between 340/7 and 366/7 weeks’ gestation were monitored simultaneously with a Doppler/tocodynamometer system and a wireless fetal-maternal abdominal surface electrode system. Fetal and maternal heart rate and uterine contraction data from both systems were compared. Reliability was measured by the success rate and percent agreement. Deming regression and Bland-Altman analysis estimated the concordance between the systems. Uterine contractions were assessed by visual interpretation of monitor tracings. Results: The success rate for the surface electrode system was 89.5 (95% CI 85.7,93.3)% and for ultrasound 88.4 (84.9,91.9)%; p=0.73, with a percent agreement of 88.1 (84.2,92.8)%. Results were uninfluenced by the subjects’ body mass. The mean Deming slope was 1.0 and the y-intercept -3.0 bpm. Bland-Altman plots also showed a close relationship between the methods, with limits of agreement <10 bpm. The percent agreement for maternal heart rate was 98.2 (97.4,98.8)% and for uterine contraction detection was 89.5 (85.5,93.4)%. Conclusions: Fetal heart rate and uterine contraction monitoring at 34-366/7 weeks using abdominal surface electrodes was not inferior to Doppler ultrasound-tocodynamometry for fetal-maternal assessment. Registration: clinicaltrials.gov/February 20, 2017/ Identifier NCT03057275

Evaluation and patient experience of wireless noninvasive fetal heart rate monitoring devices

“…It is important that the performance of the NI‐FECG device is high in both preterm and term monitoring, as prolonged FHR monitoring can be used throughout pregnancy to detect clinical deterioration. Reliable and accurate performance of NI‐FECG devices for MHR measurements has been reported previously 19,23 . Previous research has shown that women prefer the comfort of the NI‐FECG device over the DU device 18,26 .…”

“…Monica-AN24, 17,20,21,25,26 Monica-Novii 18,19 and Nemo. 23,24 Other commercial NI-FECG devices known to the authors are: Fetal Lite and Meridian-M110.…”

“…Previous studies on late preterm and term NI‐FECG monitoring have reported reliable and accurate FHR registrations. These studies used either DU or invasive fetal scalp electrode as reference standard 4,16–24 . In contrast, conflicting results on performance have been reported in the literature for preterm NI‐FECG monitoring 20,25,26 .…”

“…These studies used either DU or invasive fetal scalp electrode as reference standard. 4 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 In contrast, conflicting results on performance have been reported in the literature for preterm NI‐FECG monitoring. 20 , 25 , 26 Our study also showed conflicting results in preterm monitoring between NI‐FECG devices.…”

“…Reliable and accurate performance of NI‐FECG devices for MHR measurements has been reported previously. 19 , 23 Previous research has shown that women prefer the comfort of the NI‐FECG device over the DU device. 18 , 26 In addition, reported skin irritation from the electrodes does not prevent women from reusing the NI‐FECG.…”