OBJECTIVE: To show the importance of the anthropometrical relationships in the nutritional assessment of premature infants, during the first month of life. METHODS: Longitudinal prospective study of premature infants (birth weight <1,500g and gestational age <37 weeks). Weight, length, cephalic circumference (CC), and brachial circumference (BC) were measured. The following anthropometrical relationships were calculated (average and standard deviation): ponderal index (PI), body mass index (BMI) and the BC/CC ratio. The correlation between anthropometrical parameters and the anthropometrical relationships were studied by Pearson coefficient in the three study periods (birth, 14 and 28 days). RESULTS: Fifty-five premature newborn infants were included (54.5% female): birth weight 1,076.70±286.70g and gestational age 30.0±2.10 weeks. The PI was, at birth, 2.28±0.20, evolving to 2.00±0.20 (14 days) and 2.17±0.20 on the 28th day. The BMI was 8.20±1.10 (birth), 7.60±1.00 on the 14th and 8.60±1.20 on the 28th day. The BC/CC ratio was 0.21±0.02 at birth, 0.19±0.02 on the 14th and 0.21±0.02 on the 28th day. Amongst the correlations, the PI showed the least correlation, followed by the BC/CC ratio. The BMI presented high correlation with the anthropometrical parameters. CONCLUSIONS: PI, BMI and the BC/CC ratio presented significant increases between the 14th and the 28th day of life, but not between birth and 28th day. The BMI was the most reliable anthropometrical relationship, since it showed a real growth after the second week, surpassing birth values.
nutrition assessment; anthropometry; infant; premature
