Objective. Approximately 90% of infants who develop necrotizing enterocolitis (NEC) do so after being fed. Previous prospective studies have shown that infants given small enteral feedings for the first 7 to 10 days of feeding do not have an increased risk for NEC compared with those given no feedings. Although neonatologists now commonly increase feeding volumes, no study has compared the risk for NEC between infants fed these small volumes and those fed volumes that are increased slowly. The purpose of this study was to compare the risks and benefits of small and increasing feeding volume.
Methods. In a randomized, controlled trial, we randomly assigned 141 preterm infants in the newborn intensive care unit to be fed 10 days using 1 of 2 schedules. One group was fed 20 mL/kg/d for the first 10 study days (minimal). The other group (advancing) was fed 20 mL/kg/d on study day 1; feeding volume was increased by 20 mL/kg/d up to 140 mL/kg/d, which was maintained until study day 10. The main outcome measure was incidence of NEC; secondary outcomes were maturation of intestinal motor patterns, time to reach full enteral feedings, and incidence of late sepsis.
Results. The study was closed early because 7 infants who were assigned to advancing feeding volumes developed NEC, whereas only 1 infant fed minimal feeding volumes did, or 10% versus 1.4%. Although infants who were fed minimal volumes established full enteral feeding volumes later than infants who were fed advancing volumes, maturation of intestinal motor patterns and the incidence of late sepsis and feeding intolerance was similar in the 2 groups.
Conclusion. Given that advancing feeding volumes increase the risk of NEC without providing benefits for motor function or feeding tolerance, neonatologists should consider using minimal feeding volumes until future trials assess the safety of advancing feeding volumes.
Sirs:
Berseth et al (1) report the outcome of a randomized comparison of outcomes from infants fed either a small volume of milk for 10 days before progression or fed a steadily increasing quantity of milk from the start. In keeping with their hypothesis, the authors report a significantly higher incidence of necrotizing enterocolitis (NEC) among the infants with progressive feeds. The results of this study are unique in the implications for a prolonged period of low volume introductory feeds.
This study is from an institution with a long history of trials of feeding regimes, including one that compares the use of early trophic feeds to a similar period of NPO. (2) It is therefore surprising that neither Berseth’s group nor the accompanying editorial (3)offers any discussion of the data presented in the table that indicates the babies were NPO for about 10 days before entering the trial. This is contrary to most if not all current recommendations, including Shanler (2). Furthermore, 5 of 8 babies who developed NEC were fed after a week of age. Also evident in the tables is the fact that the infant in the delayed progression group who developed NEC was on full feeds when NEC occurred, 23 days after feeds started. Among the 7 infants in the early progression of feeds, the intervals from start of feed to NEC were 20, 21, 9, 7, 29, 9, and 12 days. Four of the 7 would have been on progressing or full feeds even had they been in the delayed group. While I don’t disagree with the authors’ recommendation to be very cautious about feeding babies, I think they should modify their recommendations. Babies should be fed early, even if only trophic feeds (20 ml/kg/d), but if feedings are delayed beyond the first week of life, then trophic feeds should be provided for up to a week before progression is conducted slowly and cautiously.
To comment on the cost of NEC and not comment on the cost of slow progression of feeding is disingenuous. Only two of the 8 NEC cases needed surgery, one from each feeding group. The survival rates were the same in both groups, while the length of venous catheter placement and hospital stay were increased 12 to 14 days in the group with delayed progression of feedings. Given the number needed to treat to prevent one case of NEC (10.6), more than 120 patient days are needed to prevent the one case of NEC. At $1000/d, this is $120,000. At $2000/d, this is $240,000. This is comparble to the cost of NEC. We should know the longer term outcome of the groups before we can decide if the expense is appropriate.
Finally, I would like to know why the authors chose a quasi- randomization process rather than a more acceptable assignment process like sealed envelopes with the assignments inside.
1. Berseth CL., Bisquers JA, & Paje VU, 2003. Prolonging small feeding volumes early in life decre4ases the incidence of necrotizing enterocolitis in very low birth weight infants. Pediatrics. 2003; 111: 529 -534.
2, Shanler RJ, Shulman RJ, Lau C, et al. Feeding strategies for premature infants: randomized trial of gastrointestinal priming and tube feeding method. Pediatrics. 1999;103: 434-439.
3. Kliegman RM. The relationship of neonatal feeding practices and the pathogenesis and prevention of necrotizing enterocolitis. Pediatrics. 2003;111: 671-672.