title: Newborn adiposity measured by plethysmography is not predicted by late gestation two-dimensional ultrasound measures of fetal growth.
abstract: Noninvasive measures of fetal and neonatal body composition may provide early identification of children at risk for obesity. Air displacement plethysmography provides a safe, precise measure of adiposity and has recently been validated in infants. Therefore, we explored relationships between term newborn percent body fat (%BF) measured by air displacement plethysmography to 2-dimensional ultrasound (2-D US) biometric measures of fetal growth and maternal and umbilical cord endocrine activity. A total of 47 mother/infant pairs were studied. Fetal biometrics by 2-D US and maternal blood samples were collected during late gestation (35 wk postmenstrual age); infants were measured within 72 h of birth. Fetal biometrics included biparietal diameter, femur length, head circumference, abdominal circumference (AC), and estimated fetal weight (EFW). Serum insulin, insulin-like growth factor (IGF) 1, IGF binding protein-3, and leptin concentrations were measured in umbilical cord and maternal serum. The mean %BF determined by plethysmography was 10.9 +/- 4.8%. EFW and fetal AC had the largest correlations with newborn %BF (R(2) = 0.14 and 0.10, respectively; P < 0.05); however, stepwise linear regression modeling did not identify any fetal biometric parameters as a significant predictor of newborn %BF. Newborn mid-thigh circumference (MTC; cm) and ponderal index (PI; weight, kg/length, cm(3)) explained 21.8 and 14.4% of the variability in %BF, respectively, and gave the best stepwise linear regression model (%BF = 0.446 MTC + 0.347 PI -29.692; P < 0.001). We conclude that fetal growth biometrics determined by 2-D US do not provide a reliable assessment of %BF in term infants.
authors.affiliation: Center for Pediatric Nutrition Research, University of Utah, Salt Lake City, UT 84158, USA. laurie.moyer-mileur@hsc.utah.edu
authors.forename: Laurie J
authors.initials: LJ
authors.lastname: Moyer-Mileur
authors.forename: Hillarie
authors.initials: H
authors.lastname: Slater
authors.forename: J Anne
authors.initials: JA
authors.lastname: Thomson
authors.forename: Nicole
authors.initials: N
authors.lastname: Mihalopoulos
authors.forename: Jan
authors.initials: J
authors.lastname: Byrne
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
mesh_terms: D000273:Adipose Tissue; D050154:Adiposity; D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D049628:Body Size; D005260:Female; D047109:Fetal Development; D020567:Fetal Weight; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods*; D011247:Pregnancy; D016216:Ultrasonography, Prenatal / Q000379:methods; D055815:Young Adult