The identified trials provide only low quality evidence about the effects of feeding preterm infants  with protein hydrolysate versus st and ard formula .
The existing data did not support conclusions that feeding with protein hydrolysate affects the risk of feed intolerance or necrotising enterocolitis .
BACKGROUND When human milk is not available for feeding preterm infants , protein hydrolysate rather than st and ard cow 's milk formulas ( with intact proteins ) are often used because they are perceived as being tolerated better and less likely to lead to complications .
However , protein hydrolysate formulas are more expensive than st and ard formulas , and concern exists that their use in practice is not supported by high- quality evidence .
OBJECTIVES To assess the effect of feeding preterm infants with hydrolysed formula ( versus st and ard cow 's milk formulas )  on the risk of feed intolerance , necrotising enterocolitis , and  other morbidity and mortality in preterm infants .
Nutritional evaluation of various protein hydrolysate formulae in term infants during the first month of life
The aim of the study was to compare , during the first month of life , growth parameters , biochemical indices of protein metabolism and plasma amino acid concentrations in newborn infants fed either human milk ( n = 23 ) , three different whey hydrolysate formulae ( WHF 1 , n = 13 ; WHF 2 , n = 10 ; WHF 3 , n = 13 ) , a soy-collagen hydrolysate formula ( SCHF n = 18 ) or a whey-casein hydrolysate formula ( WCHF , n = 20 ) .  Growth parameters and the various protein concentrations determined in the infants fed WHF 1 and WHF 2 were similar to the values observed with human milk . With WHF 3 , growth in weight , length and head circumference and serum total protein concentrations were reduced significantly whereas blood urea nitrogen was increased . With SCHF , growth in weight and length as well as serum total protein and transferrin concentration were decreased significantly , whereas serum IgG concentration was increased . With WCHF growth in length and serum transferrin concentration were decreased compared to the human milk group . In the various groups , the plasma amino acid pattern reflected the amino acid content of the formula . Whey hydrolysate formula induced mainly an increase in threonine and a decrease in tyrosine concentrations .  Soy-collagen hydrolysate formula led to an increase of non-essential amino acids , such as glycine and hydroxyproline , and a decrease in plasma lysine and cystine .  Whey-casein hydrolysate formula induced a plasma amino acid pattern close to the profile observed with human milk . Nevertheless , the plasma concentrations of most of the various amino acids were higher . ( ABSTRACT TRUNCATED AT 250 WORDS
The identified trials provide only low quality evidence about the effects of feeding preterm infants  with protein hydrolysate versus st and ard formula .
The existing data did not support conclusions that feeding with protein hydrolysate affects the risk of feed intolerance or necrotising enterocolitis .
BACKGROUND When human milk is not available for feeding preterm infants , protein hydrolysate rather than st and ard cow 's milk formulas ( with intact proteins ) are often used because they are perceived as being tolerated better and less likely to lead to complications .
However , protein hydrolysate formulas are more expensive than st and ard formulas , and concern exists that their use in practice is not supported by high- quality evidence .
OBJECTIVES To assess the effect of feeding preterm infants with hydrolysed formula ( versus st and ard cow 's milk formulas )  on the risk of feed intolerance , necrotising enterocolitis , and  other morbidity and mortality in preterm infants .