In the 22 newborn infants, mean range for age was 10.6 (6-19) days; gestational age at birth 39.9 (37.1-40.8) weeks; weight 3.3 (2.5-3.9) kg; length 53.1 (47-57) cm; WC 34 (29-39) cm; IA-AT 18 (8-32) [cm.sup.3], SCA-AT 104 (59-202) [cm.sup.3]; US-visceral depth 2.0 (1.2-3.0) cm; and US-subcutaneous abdominal depth 0.30 (0.2-0.4) cm.
IA-AT showed moderate positive correlations with US-visceral depth (r = 0.48; P = 0.02) and US-subcutaneous abdominal depth (r = 0.52; P = 0.01), and these were higher than with any anthropometric variable (Table 2).
In contrast, mean US-subcutaneous abdominal depth and skinfold thickness did not change with age.
In contrast, US-subcutaneous abdominal depth at both 3 and 12 months was positively associated with all measures of current body size (P < 0.005).
In contrast, US-subcutaneous abdominal depth at 3 months was positively associated with skinfold thickness at birth (P = 0.004), but not at age 12 months (P = 0.1) and no associations remained on adjustment for current skinfolds (Table 6).
Our validation study results showed that US abdominal depth provides acceptable accuracy in estimating IA-AT and SCA-AT volumes assessed by MRI in infants.
Therefore, we consider that US abdominal depth is suitable to rank infants with higher or lower abdominal adipose tissue volumes.
In the CBGS cohort study, we found that infants with lower skinfold thickness at birth tended to have lower subcutaneous abdominal depth at age 3 months, but greater visceral depths at ages 3 and 12 months, suggesting a differential regulation of these adipose tissue compartments.
US-visceral depth US-subcutaneous abdominal depth 3 months 12 months 3 months 12 months Anthropometry at 3 months Weight SDS 0.02 0.31 ** Length SDS -0.05 0.20 ** Ponderal index SDS 0.11 * 0.27 ** Mean of skinfolds SDS 0.05 0.31 ** Anthropometry at 12 months Weight SDS 0.03 0.30 ** Length SDS 0.00 0.11 ** Ponderal index SDS 0.04 0.26 ** Mean of skinfolds SDS 0.10 * 0.30 ** (1) SDS: sex-and age-adjusted standard deviation scores.
Ultrasound (US) Abdominal Depths. US-visceral depth and US-subcutaneous-abdominal depth were measured using a Logiq Book XP ultrasound, with a 3C MHZ -RS abdominal curved array transducer (both from GE Healthcare, Bedford, UK).