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 .
[Effects of extensively hydrolyzed protein formula on feeding and growth in preterm infants: a multicenter controlled clinical study].
OBJECTIVE To study the effects of extensively hydrolyzed protein formula ( eHF ) on the feeding and growth in preterm infants through a multicenter controlled clinical study . METHODS Preterm infants admitted to eight upper first-class hospitals in China between February 2012 and December 2013 were r and omly selected . They were divided into two observation groups and two control groups . The first observation group consisted of preterm infants with a gestational age of < 32 weeks , who were fed with eHF for 10 - 14 days after birth and then with st and ard preterm formula ( SPF ) until discharge . The second observation group consisted of preterm infants with a gestational age of 32 - 34 weeks , who were fed with SPF after birth , but were switched to eHF ( 7 - 14 days ) if suffering feeding intolerance at 6 - 8 days after birth . The two control groups with corresponding gestational ages kept to be fed with SPF after birth . Clinical data were recorded to compare feeding condition , physical growth , blood biochemical indices , and major complications between different groups . RESULTS A total of 328 preterm infants were enrolled . Preterm infants with a gestational age of < 32 weeks in the observation group had a significantly shorter meconium evacuation time than in the corresponding control group ( P<0.05 ) . They also had significantly lower levels of serum total bilirubin at weeks 1 and 2 after birth compared with the control group ( P<0.05 ) . The observation group needed more time in reaching enteral nutrition ( EN ) basic energy uptake of 50 kcal/(kg·d ) , partial parenteral nutrition ( PPN ) , hospitalization , and corrected gestational age at discharge compared with the controlled infants ( P<0.05 ) . There was no difference in the incidence of extrauterine growth retardation ( EUGR ) at discharge between the two groups ( P>0.05 ) . Preterm infants with a gestational age of 32 - 34 weeks in the observation group had significantly lower serum total bilirubin levels at 2 weeks after birth compared with the corresponding control group ( P<0.05 ) . They required more time in achieving EN basic energy and PPN than in the control group ( P<0.05 ) . There was no difference in the incidence of EUGR at discharge between the two groups ( P>0.05 ) . CONCLUSIONS For preterm infants  , eHF can improve gastrointestinal motility , accelerate bilirubin metabolism and excretion and does not increase the incidence of EUGR
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 .