Results of feeding a special formula to very low birth weight infants

Nutrient requirements for preterm infant formulas

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.

Nutrient needs of the preterm infant

Preterm infants exhibit special nutrient needs that differ substantially from other patient populations. Special characteristics include increased energy and protein requirements that must be addressed to prevent tissue catabolism and support growth. The immaturity of some organ systems may also complicate the administration of nutrition support. This article describes important characteristics of enteral and parenteral nutrition as it applies to the preterm infant.

Effect of protein/energy ratio on growth and behavior of premature infants: preliminary findings

Premature infants weighing less than 1550 gm at birth were randomly assigned to receive one of three formulas identical in composition except for protein content (2.2, 2.7, and 3.2 gm.100 kcal-1) to determine the effects on growth, protein nutritional status, and behavior. Data collected for 2 weeks from the time of achieving an enteral energy intake of 100 kcal.kg-1.day-1 included measurements of weight, length, head circumference, and skin-fold thickness, and concentrations of plasma amino acids, serum total protein, prealbumin, retinol-binding protein, and urea nitrogen. In a subset of infants, behavior was assessed at the end of the feeding study with the Neonatal Behavior Assessment Scale. Except for the concentrations of plasma amino acids, there were no significant differences in growth or in other biochemical measurements among the three groups, but there were significant differences in the orientation, habituation, and stability clusters of the behavior assessment. Further, there were significant correlations between the plasma amino acid values and the behavioral clusters. These preliminary data suggest a relationship between protein intake in the neonatal period and behavioral outcome at the end of the feeding period in the absence of differences in growth and gross markers of protein nutritional status. The behavioral items noted to differ among the groups may indicate later cognitive outcome; detailed studies about behavioral responses to neonatal dietary intakes and later outcome seem indicated.

Growth and total body water in premature infants fed "in-utero" or "ex-utero"

Total body water and anthropometric measurements were compared in two groups of premature infants. The first group included infants with birthweights less than 1,501 g who were fed under usual clinical circumstances and studied at a bodyweight of 1,800-2,100 g ("Ex-utero"); the second group of infants had a birthweight of 1,800 to 2,100 g and were studied within the first week of life ("In-utero"). Triceps and subscapular skinfold thicknesses were significantly greater in "Ex-utero" infants than in "In-utero" infants, whereas body length was significantly greater in the latter group compared to the former. There were no difference in total body water, abdominal skinfold thickness, or midarm circumference between the two groups. These data suggest that feeding premature infants a standard premature infant formula under established guidelines leads to differences in body and fat distribution but not total body water compared to infants nourished "in utero".