The Noninvasive Fetal Electrocardiogram During Labor: A Review of the Literature

Importance The introduction of the cardiotocogram (CTG) during labor has not been found to improve neonatal outcome. The search for a more reliable, less invasive, and patient-friendly technique is ongoing. The noninvasive fetal electrocardiogram (NI-fECG) has been proposed as one such alternative. Objectives The aim of this study was to review the literature on the performance of NI-fECG for fetal monitoring during labor. Following the PRISMA guidelines, a systematic search in MEDLINE, EMBASE, and Cochrane Library was performed. Studies involving original research investigating the performance of NI-fECG during labor were included. Animal studies and articles in languages other than English, Dutch, or German were excluded. The QUADAS-2 checklist was used for quality assessment. A descriptive analysis of the results is provided. Results Eight articles were included. Pooled analysis of the results of the separate studies was not possible due to heterogeneity. All studies demonstrate that it is possible to apply NI-fECG during labor. Compared with Doppler ultrasound, NI-fECG performs equal or better in most studies. Conclusions and Relevance NI-fECG for fetal monitoring is a promising noninvasive and patient-friendly technique that provides accurate information. Future studies should focus on signal quality throughout labor, with the aim to further optimize technical development of NI-fECG. Target Audience Obstetricians and gynecologists, family physicians. Learning objectives After completing this activity, the learner should be better able to interpret the performance of both noninvasive fetal electrocardiography and Doppler ultrasound for fetal heart rate monitoring during labor; assess the advantages and disadvantages of monitoring fetal heart rate with the current noninvasive fetal electrocardiogram during labor; and summarize the definitions of the different performance measures.