Heart Rate Monitoring in Newborn Babies: A Systematic Review

Background: Around 10% of newborn infants require assistance during transition after birth. Heart rate (HR) is the most important clinical indicator to evaluate the clinical status of a newborn. Aim: Our study aimed to review all established and novel methods to detect HR in babies giving special consideration to non-invasive techniques. Methods: We performed a systematic literature search on the following databases: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL. The inclusion criteria were studies on methods to detect HR in both term and preterm infants in comparison to one of the current gold standards: pulse oximetry (PO) or electrocardiography (ECG) published in the last 15 years. Two independent reviewers screened titles and abstracts for eligibility. Data extracted in an Excel table were analysed to produce a narrative review structured around the type of monitoring, identified obstacles in use, as well as methods to overcome these limitations. Results: The search revealed 649 studies after duplicates were removed. Full article analysis was performed on 26 studies of which 25 met the inclusion criteria. Well established methods such as auscultation and palpation, although rapid and easily available, have been shown to be inaccurate. ECG and PO were both more precise but the delay in obtaining a reliable HR signal from birth often exceeded 1-2 min. Novel sensors offered the advantages of minimally obtrusive technologies but have limitations mainly due to movement artefact, bad sensor coupling, intermittent measurement, and poor-quality recordings. Conclusions: The limitations of existing methods have a potential impact on short- and long-term morbidity and mortality outcomes. The development of a technological solution to determine HR accurately and quickly in babies at birth has immense implications for further research and can guide interventions, such as placental transfusion and resuscitation.