Evidence Hub

Ambulatory foetal ECG monitoring in low and high-risk pregnancies (AMBER2): a prospective cohort study protocol

Pegorie C, Liu B, Thilaganathan B, Bhide A

BMJ open, 2025

Abstract

Introduction: Measuring foetal heart rate (FHR) is critical for assessing foetal well-being, and traditional cardiotocography (CTG), though effective, has limitations such as cost, accessibility and observer bias. Newer non-invasive foetal ECG (NIFECG) devices offer more precise, reliable metrics for FHR variability and could enable remote monitoring, potentially improving early detection of foetal complications like hypoxia and stillbirth.

Methods and analysis: This is a single-centre prospective cohort study taking place in a tertiary maternity unit in the UK. Women with a singleton pregnancy over 26+0 weeks will be approached for participation in the control, foetal growth restriction (FGR) or diabetic groups. The NIFECG home monitoring schedule is 60 min daily for 7 days in the control group, daily from diagnosis until delivery for the FGR group, and daily from 36 weeks until delivery in the Insulin-dependent diabetic group. Longitudinal FHR raw ECG signals will be collected from participants across different gestational age ranges. Reference standards for FHR variability using metrics such as short-term variation, phase-rectified signal averaging acceleration and deceleration capacity will be established. The study will also aim to explore differences in FHR variability in FGR cases against controls and propose safety thresholds to guide decision-making for delivery.

Ethics and dissemination: Approvals have been obtained from the London Stanmore Research Ethics…

How strong is the evidence?

Evidence Hub reads this as a clinical trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free