By Gene Emery
(Reuters Health) - The debate over how quickly to increase the milk intake for preterm infants has new evidence suggesting that speed doesn't seem to matter.
In tests of two increments, 30 ml per kilogram of body weight per day or 18 ml per kg, the rates of survival, sepsis, necrotizing enterocolitis and problems with neurodevelopmental disability were not significantly different.
The study, published by the New England Journal of Medicine, was done at 55 hospitals, nearly all in the United Kingdom.
Earlier, limited studies had suggested that slow advancement of enteral feeding volumes might lower the odds of necrotizing enterocolitis but raise the risk of late-onset sepsis.
The new test compared the health of 1,224 premature infants who received faster-increment feeding with 1,246 babies whose milk consumption grew at the slower rate. All were born before 32 weeks of gestation or had a birth weight below 1,500 g.
The 24-month rates of survival without moderate or severe neurodevelopmental disability were 65.5% with faster feeding and 68.1% with slower feeding (P=0.16).
The late-onset sepsis rate was 29.8% with faster feeding and 31.1% with slower feeding, a non-significant difference (adjusted risk ratio of 0.96 with a 95% confidence interval of 0.86 to 1.07).
And while 5.0% of the babies who got their milk faster developed necrotizing enterocolitis, the rate was a comparable 5.6% in the children who were fed more slowly (adjusted risk ratio of 0.88 with a confidence interval of 0.68 to 1.16).
The team also found no difference in secondary outcomes such as death before discharge, mean duration of parenteral feeding or the time needed to reach full milk feeding volume of 150 ml per kg of body weight.
The death rate in the two groups was 5.6% among fast feeders and 6.2% in the slow feeding group. Rates of duration in intensive care or overall hospital stay were not significantly different either.
The rate of moderate or severe motor impairment was higher in the faster-feeding group, with a rate of 7.5% versus 5.0% in the slower-fed group, but the difference was barely significant (adjusted risk ratio of 1.48 with a 95% confidence interval of 1.02 to 2.14).
Among all the subgroups of babies analyzed, the only one that showed a difference was among infants who were only fed formula. Their rates of survival without moderate or severe neurodevelopmental disability were 40% in the faster-fed group versus 70% in the slower-fed group, but only 70 of the 2,465 babies with complete data on milk type were fed formula exclusively.
That "probably represents a chance finding," the researchers note.
"Subgroup analyses of higher-risk infants were reassuring, because there was no suggestion of worse outcomes with faster increments than with slower increments," they write.
The team cautioned, however, that the "infants were a median of 4 days old at commencement of the intervention, and therefore the trial does not inform the relative safety of these feeding volume increments in the first few days after birth. Further study would be needed to address enteral feeding in these infants, other speeds of advancing feeding volumes, and different milks. Infants born at extremely early gestational ages or with an extremely low birth weight may react differently than other infants to the speed of increasing feeding volumes."
The study is known as the Speed of Increasing Milk Feeds Trial (SIFT). Repeated attempts to interview the chief author, Dr. Jon Dorling of Dalhousie University in Halifax, Canada, were unsuccessful.
N Engl J Med 2019.