[Weight/length ratio: is it a good index to assess the nutritional status of full-term newborns?].

Objective: An accurate assessment of the nutritional status of an infant at birth is very important, since it provides information on early identification of pathological events related to intrauterine growth acceleration or retardation. Anthropometric ratios such as weight/length and mid-arm circumference/head circumference may be used as alternative tools for this purpose. The main objective of this study was to verify the correlation between triceps skinfold thickness with Rohrer Index, Body Mass Index, weight/length ratio, and mid-arm circumference/head circumference ratio.

Methods: A cross-sectional study was carried out with 390 full-term newborns delivered at the Maternity Ward of Instituto Materno Infantil of Pernambuco, from May to July 1999. The newborns had their birthweight, length, head and mid-arm circumferences and triceps skinfold thickness measured.

Results: The results showed that among the anthropometric indices studied the weight/length ratio showed the strongest correlation with triceps skinfold thickness (r=0.63, p<0.001) followed by mid-arm circumference/head circumference ratio (r=0.59, p<0.001). Rohrer index showed the weakest correlation (r=0.43, p<0.001). Multiple linear regression analyses revealed that weight/length ratio correlated best with skinfold thickness.

Conclusions: We concluded that among the studied indices, weight/length ratio showed to be the best alternative to assess the nutritional status of infants at birth.