A hospital-based cohort study of gender and gestational age-specific body fat percentage at birth

• Published in: Pediatric research Vol. 89; no. 1; pp. 231 - 237
• Main Authors: Lutz, Tracey Leigh, Burton, Alice Elizabeth, Hyett, Jon Anthony, McGeechan, Kevin, Gordon, Adrienne
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-01-2021; Nature Publishing Group
• Subjects: Body fat; Clinical Research Article; Cohort analysis; Gender; Gestational age; Medicine; Medicine & Public Health; Newborn babies; Nutritional status; Pediatric Surgery; Pediatrics
• ISSN: 0031-3998; 1530-0447
• DOI: 10.1038/s41390-020-0879-5

Background
Birthweight is the most commonly used proxy marker but does not adequately define true nutritional status. Modalities like DXA (dual energy x-ray absorptiometry) and TOtal Body Electric Conductivity (TOBEC) have been validated to assess body composition but their accuracy in neonates has not been established. The PEAPOD (COSMED, Rome Italy) has been validated as an accurate tool for measuring percentage body fat (%BF) in newborns. The study aim was to determine the gender-specific %BF percentiles at different gestations (35–41 weeks) for a healthy population of newborn infants. A secondary aim was to determine whether there is any relationship between %BF and neonatal condition at birth (cord gas measurement).
Methods
%BF was measured using air displacement plethysmography (PEAPOD) within 6 h of birth.
Results
There is an increase in the mean %BF with increasing gestation for female and males from 36 weeks’ gestation in the 7667 infants who underwent assessment. Females have a higher %BF than their male equivalents. There was no correlation between %BF and cord pH.
Conclusion
Gender and gestation are both important in determining the quantiles and mean %BF at birth. There was no correlation between low cord pH and %BF.
Impact
Measuring the percentage body fat (PEAPOD) at birth is a useful marker of an infant’s nutritional status.
This is the largest hospital-based cohort of gestational age and gender-specific %BF in healthy newborns.
The normative graphs from this study will help to accurately determine high-risk infants with low %BF so they can be monitored appropriately.