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Updated: May 27, 2025

Evaluation of Fluid Overload by Bioelectrical Impedance Vectorial Analysis
Published on: August 17, 2022
Bioelectrical impedance vector (BIVA) reference values for healthy term newborns 1-2 days old
Nallely Bueno-Hernández1, Jesús Carlos Briones-Garduño2, Miguel Ángel Fonseca-Sánchez1
1Laboratorio de Proteómica e Inmunometabolismo, Hospital General de México "Dr. Eduardo Liceaga", Mexico City 06720, Mexico.
Insights
Bioelectrical impedance vector analysis (BIVA) reference values for newborns were established. Significant differences were found compared to other populations, potentially due to ethnicity or BIVA assessment techniques.
Area of Science:
- Physiology
- Biomedical Engineering
Background:
- Bioelectrical impedance vector analysis (BIVA) assesses body fluids and nutritional status using reference ellipses.
- Population-specific BIVA ellipses are influenced by ethnicity, BMI, sex, and age.
Purpose of the Study:
- To establish BIVA reference values for healthy, term newborns aged 1-2 days.
- To compare these values with previously reported newborn populations.
Main Methods:
- A cross-sectional study collected bioelectrical impedance data from healthy, term newborns within 48 hours of birth.
- Mean impedance vector tolerance ellipses (50%, 75%, 95%) were constructed.
Main Results:
- Significant differences in mean impedance vectors were observed between populations.
- Similarities were found only with one of the four previously reported populations.
- No differences were linked to mode of delivery or newborn sex.
Conclusions:
- BIVA reference ellipses for healthy term newborns (1-2 days) were successfully constructed.
- Observed differences suggest ethnic influences or variations in BIA assessment techniques impact BIVA ellipses in newborns.
Background:
Bioelectrical impedance vector analysis (BIVA) is a valuable tool for assessing individuals' body fluids and nutritional status by examining the impedance vector's position on the mean reference impedance vector tolerance ellipses from healthy populations. Nevertheless, differences in BIVA tolerance ellipses have been reported between populations with different ethnicities, body mass index (BMI), sex, and age.
Aim:
To construct BIVA reference values for healthy newborns aged 1-2 days born to term and compare them to those previously reported for newborns from different populations.
Methods:
A cross-sectional study was conducted using bioelectrical impedance data collected within the first 48 h after birth from healthy, term newborns with healthy mothers. The mean impedance vector 50 %, 75 %, and 95 % tolerance ellipses were constructed and compared with those previously reported for other newborn populations.
Results:
The healthy newborns' mean impedance vector showed significant differences between populations, with similarities observed only between our newborn population and one of the four previously reported populations. No vector displacement was found related to the mode of delivery or sex of the newborns.
Conclusions:
The mean impedance vector tolerance ellipses for healthy term newborn population aged 1-2 days were constructed. Our results show that there are differences in the mean impedance vector compared to other BIVA newborn studies, which could result from the influence of ethnic background on BIVA tolerance ellipses or be due to differences in the technique for BIA assessment.

