Accuracy of a Noninvasive, Wearable, Wireless, ECG-Based, Intrapartum Monitoring Tool Against the Conventional Ultrasound-Based CTG

Abstract

Background: Most conventional cardiotocographs (CTG) work on the ultrasound principle and are heavily used by doctors to measure fetal heart rate (FHR) and uterine contractions (UCs). Despite their widespread usage, they have limitations with accessibility, portability and ease of use. Electrocardiogram (ECG) which relies on electrical signals gives a far superior signal during labor, yet it is ineffective to measure FHR unless an invasive scalp electrode is inserted. Noninvasive fECGs (ni-fECG) are still subject to constant research and validation. The ni-fECG device is a novel, ECG and electromyography (EMG)-based medical device that measures FHR, UC and maternal heart rate (MHR) continuously. It is portable, wearable and easy to use. This study aimed to assess the accuracy of the ni-fECG device with the conventional ultrasound-based CTG.

Methods: A prospective observational study was conducted on 282 pregnant women. The inclusion criteria included women ≥ 28 weeks of gestational age with singleton pregnancy and cephalic presentation. The procedure used in both the devices to monitor FHR and UC was explained to the participants. Data analysis was done using Python Jupyter Notebook.

Results: The accuracy for baseline heart rate, FHR and UC was found to be 97.37%, 91.3% and 70.27%, respectively. BMI and maternal age did not have a significant impact on the comparative accuracy.

Conclusion: With further improvements in UC accuracy the ni-fECG device could be a viable alternative to CTGs.

Keywords: Cardiotocograph; Electrocardiogram; Fetal heart rate; Noninvasive fetal ECG; Ultrasound; Uterine contractions.