Work

Assessing signal loss, accuracy, and acceptability of an ambulatory fetal electrocardiography with cardiotocography in the antepartum and intrapartum phases

Year: 2025

Type: article

Abstract: INTRODUCTION: Electronic fetal heart rate (FHR) monitoring is integral to antepartum and intrapartum care to detect fetal compromise, reducing neonatal morbidity and mortality. Conventional wired cardiotocography (CTG) limits mobility, birthing positions, and potentially increases instrumental births. Wireless non-invasive fetal electrocardiography (NIFECG) aims to address these challenges. However, NIFECG has limitations, including signal interference and limited accuracy data for FHR and uterine contraction (UC) monitoring. This study aimed to (i) quantify acceptable NIFECG traces based on signal loss in women ≥37 weeks' gestation; (ii) compare FHR and UC monitoring accuracy between NIFECG and CTG; (iii) and assess NIFECG acceptability. MATERIAL AND METHODS: A prospective cohort involving women with singleton pregnancies ≥37 weeks' gestation was conducted between August 2020 and April 2023 in KK Women's and Children's Hospital, Singapore. Women underwent 40 min of concurrent NIFECG and CTG monitoring during antepartum and intrapartum phases. Data were compared in 3.75-s epochs. Based on the International Federation of Gynecology and Obstetrics guidelines, NIFECG traces with signal loss ≤20% were accepted. FHR monitoring accuracy was assessed using Bland-Altman and Passing-Bablok regression analyses. UC monitoring accuracy was determined by a fourfold contingency table with CTG as a gold standard. Acceptability was assessed via post-monitoring feedback questionnaire. RESULTS: One hundred and three women contributed to 124 paired traces. Seventy-three traces (58.9%) were acceptable, comprising 52 antepartum (56.5%) and 21 intrapartum traces (65.6%). Bland-Altman (bias: -0.4 beats per minute, 95% limits of agreement: [-9.0, 8.1]) and Passing-Bablok (slope = 0.97, 95% confidence interval (CI) 0.97-0.98) analyses showed high agreement between NIFECG and CTG FHR measurements. NIFECG showed a specificity of 0.96 (95% CI 0.94-0.97) and sensitivity of 0.90 (95% CI 0.89-0.92) for UC monitoring. Additionally, 90.1% of women and 88.9% of nurses preferred NIFECG. CONCLUSIONS: NIFECG has comparable accuracy to CTG for FHR and UC monitoring during the antepartum and intrapartum phases and is well-accepted by women and nurses. Given that 41.1% of NIFECG traces were rejected due to signal loss, further research on improving the technology to reduce signal loss, and re-evaluating the criteria for rejecting traces is vital to achieve broader clinical implementation of NIFECG.

Source: Acta Obstetricia Et Gynecologica Scandinavica

DOI: 10.1111/aogs.70113