Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants

The introduction of progressive enteral feeds for very low birth weight (VLBW) infants is often delayed for several days or longer after birth due to concern that earlier introduction may not be tolerated and may increase the risk of necrotising enterocolitis (NEC). However, delaying enteral feeding could diminish the functional adaptation of the gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks.

To determine the effect of delayed introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in VLBW infants.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2010, Issue 4), MEDLINE (1966 to December 2010), EMBASE (1980 to December 2010), CINAHL (1982 to December 2010), conference proceedings, and previous reviews.

Randomised or quasi-randomised controlled trials that assessed the effect of delayed (more than four days' postnatal age) versus earlier introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in VLBW infants.

Data collection and analysis were performed in accordance with the standard methods of the Cochrane Neonatal Review Group.

We identified five randomised controlled trials (RCT) in which a total of 600 infants participated. The trials defined delayed introduction as later than five to seven days after birth and early introduction as less than four days after birth. Two of the trials, in which a total of 488 infants participated, only recruited growth-restricted infants with Doppler ultrasound evidence of abnormal fetal circulatory distribution or flow. Meta-analyses did not detect statistically significant effects on the risk of NEC [typical relative risk 0.89, 95% confidence interval (CI) 0.58 to 1.37] or all cause mortality (typical relative risk 0.93, 95% CI 0.53 to 1.64). Infants who had delayed introduction of enteral feeds took significantly longer to establish full enteral feeding (reported median difference three days).

Current trial data do not provide evidence that delayed introduction of progressive enteral feeds reduces the risk of NEC in VLBW infants. Delaying the introducing of progressive enteral feeds results in several days delay in establishing full enteral feeds but the clinical importance of this effect is unclear. Further RCTs are needed to give more precise estimates of the effect of delaying the introduction of enteral feeds on clinical outcomes in VLBW infants.