Indices of body proportionality in neonates

The inadequacy of using body weight alone to evaluate fetal skeletal and soft-tissue growth has long been recognized. Body proportionality indices could identify symptomatic newborn infants better than size-for-date classification. Lack of normative data precludes its being used, practically, in Chinese newborns. Thus body weight, body length, head circumference and mid-arm circumference were measured in 240 neonates appropriate for gestational age, 27-42 weeks, 960-3918 g, to construct reference indices of body proportionality: ponderal index (PI), body mass index (BMI), weight/length ratio (W/L), head circumference/body length ratio (HC/L) and mid-arm circumference/head circumference ratio (MAC/HC). All the five indices of body proportionality but HC/L were statistically correlated with gestational age (GA). For full-term newborns, PI did not correlate with GA. Furthers, the MAC/HC ratio decreased after 40 weeks' gestation. Therefore, when these indices of body proportionality are used to evaluate intrauterine nutritional status of a newborn, the appropriate standard for GA should be considered.