Continuous non-invasive electrophysiological monitoring in high-risk pregnancies: study protocol of a cohort intervention random sampling study in a tertiary obstetrical care centre in the Netherlands (NIEM-O study)

INTRODUCTION: Women with high-risk pregnancies (eg, pre-eclampsia, imminent preterm birth) are often hospitalised due to the need for foetal and maternal monitoring. They are monitored for 30-45 min up to three times a day with conventional cardiotocography (CTG). In the meantime, they reside at the hospital, but the foetal status is not monitored. Continuous foetal monitoring is currently not recommended using CTG, due to the potential temperature rise from consistent exposure to ultrasound waves. For safe 24/7 monitoring, newly developed devices using non-invasive electrophysiological cardiotocography (eCTG) instead of conventional CTG offer a promising alternative. Previous research into eCTG has shown favourable results in monitoring foetal heart rate throughout both pregnancy and labour. This study aims to investigate the effect of implementing continuous antepartum eCTG monitoring in hospitalised high-risk pregnancies on perinatal and maternal outcome. METHODS AND ANALYSIS: In this single centre prospective cohort intervention random sampling study, eligible women will be included on the Obstetric High Care of Máxima MC Veldhoven, the Netherlands. In total, 511 pregnant women with a singleton pregnancy between 23+0 and 32+0 weeks of gestation requiring hospitalisation will be recruited. Eligible women will be prospectively included in the cohort receiving standard treatment: intermittent CTG monitoring. From these women, a random sample of the prospective cohort will be offered a new monitoring method: 24/7 eCTG monitoring. For the eCTG monitoring, a wireless abdominal electrode patch, the Nemo Foetal Monitoring System will be used. Additional data from a historical cohort (2014-2019) of 1400 women receiving standard treatment will be included. Perinatal and maternal outcome, along with satisfaction levels of both patient and caregivers, will be compared between groups. ETHICS AND DISSEMINATION: The study is registered on 18 October 2022 to the Central Committee on Research Involving Human Subjects (NL82869.015.22) via https://www.toetsingonline.nl/to/ccmo_monitor.nsf/conceptabr?OpenForm and approved by the Medical Ethics Committee of Máxima MC (W22.070) on 7 November 2023. Results of the study will be disseminated in peer-reviewed scientific journals and conference presentations. TRIAL REGISTRATION NUMBER: NCT06151613.