Anthropometric assessment of nutritional status in newborn infants. Discriminative value of mid arm circumference and of skinfold thickness.

74 appropriate-for-gestational age (AGA) and 22 small-for-gestational age (SGA) caucasian infants were studied for anthropometric parameters: mid arm circumference (MAC), triceps and subscapular skinfold thickness (TSKF and SSKF) recorded at 15 and 60 s, chest circumference (cc), head circumference, birth weight and length. MAC is highly correlated with birth weight either in AGA (r = 0.936; P less than 0.001) or in SGA infants (r = 0.860; P less than 0.001). MAC is also correlated with gestational age in AGA (r = 0.850; P less than 0.001) and SGA infants (r = 0.76; P less than 0.001). Similar correlations were found between TSKF, SSKF and birth weight or gestational age. Arm muscle and fat areas are also positively correlated with birth weight and gestational age, in AGA and SGA infants. A multiple regression analysis of our data allowed a classification of the best discriminant anthropometric parameters between AGA and SGA infants. MAC, SSKF15, SSKF60 and chest circumference were selected. An equation was established in AGA infants with these four parameters giving a predictive gestational age: gestational age (weeks) = 1.216 MAC (cm)-3.588 SSKF15 (mm) + 0.263 CC (cm) + 17.9. The ratio of predicted gestational age to the real gestational age was 1.0 +/- 0.044 in AGA versus 0.896 +/- 0.034 in SGA infants. Our data suggest that MAC and SSKF provide a simple measure of body composition of neonates and a useful tool for determining the degree of maturity of a newborn independent of birth weight.