Early nutrition (first weeks-months) has a profound impact on later functional outcome. The consequences of growth failure are reduced body weight, reduced organ growth and altered structure function. Protein intake is the major driving force of weight gain in low-birth-weight infants. At 28 weeks the foetal weight is 1000gms while at 38 weeks it is 3000gms. After birth, term baby grows 30gms/day. The process of nutritional intake after birth changes from arterial to oral wherein it is difficult for preterm babies to take in food and assimilate it.
Present nutrient requirements are based upon composition of human milk and the factorial approach. The factorial approach uses estimations of weight gain and the composition of foetal tissues (carcass analysis). After discharge fully oral feeding (includes bottle feeding, breast feeding or a combination of both) is required. Physiologically stability with or without home support is required. A physiologically stable has the ability to maintain their temperature in an open cot. Normal body temperature is defined as an axillary temperature of 36.1 to 37.1 degrees Celsius. The baby also has a steady weight gain at the time of discharge; steady weight gain is defined as 20 to 40gm/day.
Some challenges faced are metabolic and gastrointestinal immaturity, immunological compromise, and maternal psychosocial conditions. Reductions in sepsis and NEC have been reported for premature infants fed on breast milk, availability of milk is an issue for mothers delivering prematurely. In such instances donor pasteurized human milk has been suggested as a proxy for the mother’s own milk.
Nutritional concerns arise because the quantity of nutrients in breast milk may not meet the great nutrient needs of premature infants born weighing <1500 g. Nutritional needs are determined on the basis of intrauterine rates of growth and nutrient accretion. Also, variability in nutrient composition is both inherent to milk and imposed by circumstances of collection, storage, and distribution. Indeed, the energy and protein contents of human milk vary greatly. The most variable nutrient in human milk is fat. Concentrations of Protein, Sodium, and Zinc decline through lactation yet the nutrient needs of premature infants remain higher. The content of other nutrients such as calcium, phosphorous remain too low with respect to the needs of premature infants. Therein infants fed on unfortified human milk may lead to progressive decreases in serum phosphorus, increases in serum calcium and alkaline phosphatase. Infants having the highest alkaline phosphatase values in the hospital had as much as a 2-cm reduction in linear growth at 18 months. Technical reason towards collection, storage and delivery of milk results in decreased delivery of nutrients like Vitamin C, A and riboflavin. Indexes of protein nutritional status e.g. Blood urea nitrogen, serum albumin, total protein, and prealbumin are lower and continue to decline over time when premature infants are fed unfortified human milk. Also, growth rates in excess of I 5g/kg/day are desired. Unfortified human milk would not meet this target.