NEWBORN BODY COMPOSITION ON DAY TWO OF LIFE MEASURED USING AIR-DISPLACEMENT BODY PLETHYSMOGRAPHY
1 slide(s) – English – 2010-10-23
Background and aims: In addition to the immediate neonatal risks, fetal growth restriction has been increasingly recognised as a risk for long term metabolic disease. Most studies have relied on standardised birth weight centiles to categorise fetal growth. We wished to examine the true rate of growth abnormal fetal growth and compare this to the use of indirect methods.
Methods: Infant were recruited antenatally as part of a prospective birth cohort study, the BASELINE study. Body fat and fat free mass were measured on day 2 of life in infants using air displacement body plethesmography . Gender, gestation, birth weight(BW), weight, length, mid arm circumference (MAC), Ponderal Index (PI) were recorded .
Results: To date 200 infants have been recruited, with mean (SD) gestational age of 39.7 (1.2)weeks and mean (SD) BW = 3.520 (0.472) kg. The mean (SD) fat mass was 0.389 kg (0.272), giving a mean (SD) percentage body fat of 11(4)%. In the 22 infants with a body fat mass < 10th centile birth weight was 3.12(2.7-3.88)kg. Only one baby had a BW < 10th centile using standard centiles. MAC correlated with total body mass (R =0.705, p< 0.001) and showed a negative correlation with lean body mass R= -0.263, p< 0.001).
Conclusion: We have provided normal ranges for infant fat mass on day 2 of life. Standard birth centiles do not accurately detect low body fat or fetal growth restriction.