Application of bioelectrical impedance in newborns: an integrative review.

Objective: the objective of this study was to identify the use of bioelectrical impedance in newborns (NB), as this is an easy-to-apply and non-invasive method of measurement that can be used for distinguishing fat-free mass (FFM), fat mass (FM), and total body water (TBW). Method: this was an integrative review of the literature using the PUBMED/MEDLINE, EMBASE, Web of Science, and Virtual Health Library databases to search for original articles between 2010-2020. A total of 900 articles were retrieved; after checking for duplicity and applying the eligibility criteria, 9 were further analyzed. Results: about the results, five studies used single frequency bioimpedance, with a specific population of neonates, preterm and/or full term, and different clinical conditions. Resistance was the most studied bioelectric indicator, the phase angle is little explored, and four studies investigated body composition (FFM, FM and TBW). Studies found that preterm newborns had lower amounts of TBW, FFM, and FM than term newborns, and there were differences in body composition between sex. The phase angle was lower for preterm newborns. Babies fed babies with high protein formulas had increases in the FFM. Conclusion: there is a need for multicenter studies to define standardized methods to be used with this public.