In the United States, one in nine infants is born prematurely (before 37 weeks gestation), one of the highest rates among developed countries. Premature and very low birth weight infants (those weighing less than 1.5 kg) are especially vulnerable to complications in the NICU and particularly benefit from the anti-inflammatory and immunological components in human milk.
Due to this ever-growing evidence, the use of donor milk is rapidly emerging as the standard of care for very low birth weight infants in NICUs across the United States. In 2012, as part of its policy statement Breastfeeding and the Use of Human Milk, the American Academy of Pediatrics stated “The potent benefits of human milk are such that all preterm infants should receive human milk. Mother’s own milk, fresh or frozen, should be the primary diet, and it should be fortified appropriately for the infant born weighing less than 1.5 kg. If mother’s own milk is unavailable despite significant lactation support, pasteurized donor milk should be used.”3
Most notably, an all human milk diet dramatically reduces the risk of necrotizing enterocolitis (NEC), an inflammation of the intestine that is the most prevalent gastrointestinal emergency among preterm infants. Up to 10-12% of infants born significantly premature develop NEC and will suffer both short-term and long-term health consequences. While all premature infants have an elevated risk for NEC, those with very low birth weight are at particular risk. Newborns with certain forms of congenital heart disease are also at an increased risk for NEC, regardless of gestational age.4
Half of infants with NEC require surgery to remove the affected intestinal tissue. Of these, 25% will develop short gut syndrome, a condition where there is not sufficient intestinal tissue for adequate absorption of nutrients.
NEC has a 24% mortality rate among infants who develop non-surgical NEC, and a 40% mortality risk among infants who require surgery. NEC continues to require resources to alleviate long-term problems associated with the disease, including intestinal obstructions, failure to thrive, feeding abnormalities, short gut syndrome, parenteral nutrition-associated liver disease, and poor neurodevelopmental outcomes.
Human milk is uniquely designed for the newborn gut and provides robust protection. One study found that just 50% human milk feeding in the first 14 days of life was associated with a six-fold decrease in the odds of NEC.5 This protection appears to be dose dependent, with NEC rates increasing as the proportion of formula in the diet increases.6 Infants fed a formula-based diet were shown to have 3.5 times greater risk for developing NEC, and exposure to any amount of formula increases risk.7 Similar increase was found by Cochrane 2014 with a formula-based diet elevated NEC risk by 2.77 times.8
An exclusive human milk diet has been shown to decrease the overall incidence of NEC by up to 80% and the rate of surgical NEC by more than 90%. Those infants who acquire NEC despite having an all human-milk diet have a much more benign course of disease, recovering quickly and rarely requiring surgery.9,10,11,12,13
It is estimated that one case of NEC could be prevented for every 10 infants receiving an all human milk diet, and one case of NEC requiring surgery or resulting in death could be prevented for every eight infants receiving an all human milk diet.14
Increased Feeding Tolerance
Total Parenteral Nutrition (TPN) refers to intravenous feeding, bypassing the usual process of eating and digestion. TPN is often required in infants at 30 weeks gestation or below and in infants with certain gastro-intestinal conditions. TPN is hard on the body, costly, and is associated with vascular, hepatic, and infectious complications.
Human milk, whether maternal or donated, is associated with quicker tolerance of oral feeds, eliminating the need to initiate TPN feeding in 11-14% of premature infants or reducing the number of days on TPN.15
Human milk feeding has been associated with improved outcomes and less time on TPN16 for infants with short gut syndrome and other gastrointestinal issues. In a study of 272 infants with intestinal failure who where followed for 27.5 months, breast milk fed infants were on TPN for an average of 290 days vs. 720 days of TPN for infants not receiving breast milk.17