PLASMA AMINO ACID BALANCE IN RELATION TO PROTEIN INTAKE IN PRETERM INFANTS: WHAT IS OPTIMAL PROTEIN INTAKE?

Räihä NCR. (Department of Paediatrics in Malmö, University of Lund, Sweden). Plasma amino acid balance in relation to protein intake in preterm infants: What is the optimal protein intake? Acta Paediatr Scand, Suppl. 296:19, 1982. — The milk of a given species should be best adapted for the nutrition of the newborn of that species. This applies for the normal infant born at term and there is consequently general agreement that human milk is the most appropriate nutritional regimen for the full‐term infant. While there is agreement when the full‐term infant is concerned, this is not the case for the preterm infant whose requirements have not yet been fully determined. It has been during the late 1970s that the more common survival of infants around 1000 g at birth has been possible. It is clear, that when deciding on an optimal diet for these infants one cannot generalize and speak about an appropriate diet for “all” preterm infants but growth rate and stage of biochemical development of the particular preterm infant in question, must be considered as well. The metabolic immaturities and the time of their maturation are important when nutritional regimens of the infants are planned. During the first four to six weeks of life, depending on maturity at birth, when both amino acid synthesizing and degradating capacities are not yet fully developed, a compromise must be made, between estimated protein requirement and actual intake, in order to avoid metabolic imbalances, which may be deleterious for later intellectual performance. During this period the mothers expressed breast milk should be preferred and pooled donor milk should be added only when the mother is not providing enough. A total intake of 185 to 200 ml per kg per day should be given. When biochemical maturity of the infants has been achieved, protein intake may be increased somewhat as a supplement to breast milk. If human milk is not available and proprietary formula must be used for feeding preterm infants it must be kept in mind that formulas with a protein composition similar to that found in human milk cause less metabolic stress than do those with a protein and amino acid composition more like bovine milk.