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Researchers Recommend Earlier Feedings of Milk or Formula For Premature Babies | |
| By Sally Squires (c) 1996, The Washington Post Based on a growing number of nutritional studies, experts are revising what, when and how to feed babies, from the tiniest preemies to healthy 3 month olds. The most striking shift is the growing practice of giving very low-weight premature infants breast milk or formula within the first few days of life rather than automatically putting them on a long course of intravenous feedings. A series of studies presented last week at the annual meeting of the American Pediatric Society, the European Society for Paediatric Research and the Society for Pediatric Research highlighted various benefits of starting feedings of formula or milk as soon as possible. "We are getting a better appreciation for some of the subtle effects that one can see in preemies that's related to diet," said Robert J. Shulman at the Department of Agriculture's Children's Nutrition Center in Houston and coauthor of several of the studies presented last week. "In the past, we didn't have the technology to do these kinds of studies." For years, doctors have refused to give even small amounts of formula or breast milk to premature infants who are under about three pounds because they believed it could overwhelm their undeveloped gastrointestinal tracts. Some studies linked such early feedings to a serious complication called necrotizing enterocolitis (NEC), which destroys the lining of the intestine. About half of babies who develop the complication die, and a quarter must undergo surgery to remove their damaged intestines and thus require costly long-term medical care, said Peter Sauer, a neonatologist from the Sophia Children's Hospital in Rotterdam, the Netherlands. Feeding premature infants intravenously in the first few weeks also was thought to protect against some dangerous lung problems. If preemies had empty stomachs, the theory went, they would be less likely to spit up and less likely to aspirate the stomach contents into their lungs, where they might cause pneumonia. But findings from a number of different research groups suggest that feeding even the tiniest babies soon after birth helps stimulate a wide variety of important physical changes that promote growth and development. In a 12-center trial sponsored by the National Institute of Child Health and Human Development, researchers studied the effects of early feeding of milk or formula on 1,665 premature infants, born weighing 500 to 1,500 grams, or about 1 to 3 pounds. They found babies under the age of nine days who received small amounts of dilute formula or breast milk through a nasogastric tube, one threaded through their nose to their stomach, gained weight faster than those who did not. (All babies in the study also received intravenous feedings.) Delaying those feedings by as little as a week was associated with a lag in weight gain of 2 to 4 grams per day, the study found. Keeping babies solely on intravenous feedings appears to result in atrophy of the gastrointestinal tract, which usually doesn't last long, said Richard A. Ehrenkranz, professor of pediatrics at Yale University School of Medicine and lead author of the study. But when premature babies are fed small amounts of formula or breast milk from an early age, the feedings seem to "prime the gastrointestinal tract and make it more ready to accept" full feedings of milk or formula, he said. At Baylor College of Medicine in Houston, Shulman and his colleagues compared 20 premature infants who received small amounts of formula or breast milk as soon as five days after birth with 24 preemies who did not receive the food until they were 16 days old. Giving food early promoted activity of an important intestinal enzyme, called lactase, which breaks down the main carbohydrate found in human milk, the researchers said. How often premature babies are fed also appears to affect development, according to another study by Shulman and his colleagues at Baylor and the USDA clinical nutrition research center. All 150 premature babies in this study received intravenous feedings and then were assigned to one of two groups: One group received small amounts of continuous feeding by nasogastric tube. The second group was also fed by nasogastric tube, but received larger feedings at regular intervals throughout each 24-hour period, a process known as bolus feeding. The study found that bolus feedings were tolerated better by the babies than continuous feeding. The infants in the bolus group needed less medication to control spitting up and they had less bloating, although there was no advantage in growth. But the study found that babies fed by bolus also switched sooner to regular nursing than the babies who were fed continuously. The bolus feedings more closely mimic regular meals and "probably cause more stimulation of certain hormones that enhance intestinal developments," Shulman said. All this evidence points "to the ability of food to begin to induce the development of enzymes and other digestive processes in the premature infants," said Marilyn Escobedo, who serves on the American Academy of Pediatrics Committee on the Fetus and the Newborn. "The caution of course is that we don't have any good measures of individual maturation, so this takes a great deal of clinical expertise to know how to proceed." Fortifying feedings may also help to reduce the risk of complications in premature babies. Alexandra Howlett and Arne Ohlsson from the University of Toronto's Women's College Hospital analyzed the effects of supplementing formula fed to preemies with inositol, a sugar normally found in high levels in amniotic fluid. In the womb, babies obtain the inositol by swallowing the fluid. Premature babies frequently have low levels of inositol due to their shorter stay in the womb. Infant formula is not fortified with inositol. Three studies involving 236 premature infants were reviewed by Howlett and Ohlsson, who found a "significant reduction" in the risk of lung problems, blindness and NEC in those infants who received inositol. "We're recognizing that premature infants have different nutritional requirements than full-term babies," Howlett said, noting that a large long-term trial needs to be launched to further evaluate the use of inositol. | |