Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants

Background Early enteral feeding practices are potentially modifiable risk factors for necrotising enterocolitis in very preterm or very low birth weight (VLBW) infants. Observational studies suggest that conservative feeding regimens that include slowly advancing enteral feed volumes reduce the risk of necrotising enterocolitis. However, slow feed advancement may delay establishment of full enteral feeding and be associated with metabolic and infectious morbidities secondary to prolonged exposure to parenteral nutrition. Objectives To determine the effect of slow rates of enteral feed advancement on the incidence of necrotising enterocolitis, mortality and other morbidities in very preterm or VLBW infants. Search methods We used the standard search strategy of the Cochrane Neonatal Review Group. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12), MEDLINE, EMBASE and CINAHL (to December 2012), conference proceedings, and previous reviews. Selection criteria Randomised or quasi-randomised controlled trials that assessed the effect of slow (up to 24ml/kg/day) versus faster rates of advancement of enteral feed volumes upon the incidence of necrotising enterocolitis in very preterm or VLBW infants. Data collection and analysis Data collection and analysis was performed using the standard methods of the Cochrane Neonatal Review Group. Main results We identified five randomised controlled trials in which a total of 588 infants participated. Few participants were extremely preterm, extremely low birth weight or growth restricted. The trials defined slow advancement as daily increments of 15 to 20 ml/kg and faster advancement as 30 to 35 ml/kg. Meta-analyses did not detect statistically significant effects on the risk of necrotising enterocolitis (typical risk ratio (RR) 0.97, 95% confidence interval (CI) 0.54 to 1.74) or all-cause mortality (RR 1.41, 95% CI 0.81 to 2.74). Infants who had slow advancement took significantly longer to regain birth weight (reported median differences two to six days) and to establish full enteral feeding (two to five days). Authors' conclusions The available trial data suggest that advancing enteral feed volumes at slow rather than faster rates does not reduce the risk of necrotising enterocolitis in very preterm or VLBW infants. Advancing the volume of enteral feeds at slow rates results in several days delay in regaining birth weight and establishing full enteral feeds but the long term clinical importance of these effects is unclear. The applicability of these findings to extremely preterm, extremely low birth weight or growth restricted infants is limited. Further randomised controlled trials in these populations may be warranted to resolve this uncertainty.