Body Composition of Healthy Term Indian Newborns by Air Displacement Plethysmography: A Cross-Sectional Study

To evaluate the body composition of Indian newborns using air displacement plethysmography (ADP) and assess the correlation between fat mass percentage (FM%) and anthropometric parameters.

A cross-sectional study at a single centre in New Delhi, India, assessed the body composition of singleton, term, healthy newborns at 24-72 h of life by ADP technique using Peapod and described as FM%, fat mass index (FMI) and fat-free mass index (FFMI). Comprehensive anthropometry (head, arm, abdomen and chest circumferences; 5-site skinfold thicknesses) and parental anthropometry was also performed in a subset. Anthropometric data were converted to Z-scores using WHO Anthro software.

One hundred and forty-five newborns (73 males) were evaluated. The mean (SD) birthweight was 2882 (305) g and FM% was 7.9 (3.3). FM% correlated positively with birthweight (r = 0.27, P < 0.01); mean FM% being 6.8 (3.6), 8.0 (2.9) and 8.8 (3.4), respectively, in newborns with birthweight < 2700 g (n = 41), 2700-2999 g (n = 52) and ≥ 3000 g (n = 52) (P = 0.015), respectively. Higher maternal last trimester body mass index (BMI) was associated with higher FM% (r = 0.30, P = 0.009). Gestational age correlated with birthweight (r = 0.30, P = 0.003), and FFMI (r = 0.34, P < 0.001), but not with FM% or FMI. Maternal gestational weight gain, and dairy intake correlated with birthweight (r = 0.26, P = 0.012, and r = 0.21, P = 0.040, respectively) but not with neonatal body composition. BMI and sum of SFT (subscapular, triceps and suprailiac) showed a modest correlation with FM% (r = 0.42 and r = 0.38, P < 0.001).

Indian newborns do not demonstrate a thin-fat phenotype. FM% measured using ADP is lower than that reported in comparator populations and shows a positive association with birth weight.