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 Efficacy of Preterm Formula With a Partially Hydrolyzed Protein Source: A Randomized Pilot Study
Background Decreased nitrogen levels , calcium intestinal absorption rates , and plasma amino acid imbalances were reported for preterm infants who were fed partially hydrolyzed preterm formulas . In this pilot study , we evaluated a new formula with modified nitrogen and calcium sources . Methods During their second week of life , 16 preterm infants were r and omly assigned to one of two groups : 9 were fed the  new partially hydrolyzed formula and 7 were fed a conventional formula . Nutrient balance was performed at the end of the first month of life . Amino acid concentrations and anthropometric parameters were measured at theoretical term . Results Birth weight and gestational age ( mean ± SD ) were similar in the two groups ( 28.9 ± 7.0 weeks and 1183 ± 242 g vs. 27.7 ± 1.0 weeks and 1139 ± 162 g ) . Median nitrogen absorption rates ( 85 % vs. 89%;P = 0.03 ) and biological values ( 59 % vs. 69%;P = 0.13 ) were lower for infants who were fed the new formula than for those fed the conventional formula . After correction for difference in nitrogen intake , there was no significant difference in nitrogen retained between the two groups ( P = 0.11 ) . Plasma amino acid concentrations were also similar in the two groups . Median calcium absorption tended to be higher in the new-formula group than in the conventional-formula group ( 54 % vs. 45 % , P = 0.19 ) . At theoretical term , infants fed the conventional formula were heavier than infants fed the new formula ( 3559 ± 362 g vs. 3193 ± 384 g , P = 0.04 ) . Conclusions Because nitrogen content is 10 % higher in hydrolyzed-protein formula than in entire-protein formula , appropriate nitrogen retention , plasma amino acid profile , and mineral use can be achieved with the new partially hydrolyzed formula . Further studies with larger groups are needed to evaluate the effect on growth
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 .