Human milk (HM) is of course the natural feeding for premature infants. However, because it's nutrient content is not able to meet the extraordinarily high nutrient needs of the premature infant, and because circumstances often prevent HM from being available to the premature infant, feeding must often resort to formula. Formula offers one clear and undisputed advantage to the infant, which is that nutrient intakes match the infant's needs quite well. As a consequence, formula-fed premature infants as a rule grow better than infants fed HM. When HM is fed, it must be supplemented (fortified) with nutrients. Fortification is difficult and even when it is practiced with good intentions, nutrient intakes often remain inadequate and growth of the infant lags behind what it would have been in utero. Nevertheless, the feeding HM offers the infant very strong advantages, which make it necessary that every effort be made to secure HM for the premature baby. At the same time it mandates that strong efforts be made to fortify HM so that the infant does not pay an inordinate price in terms of slowed growth.
ESTABLISHED ADVANTAGES OF HM
The advantages of HM include protection against necrotizing enterocolitis (NEC) and sepsis, and its trophic effects. The protection against NEC was first demonstrated by Schanler and coworkers in 1999 (1). A more recent study on a larger cohort demonstrated that the feeding of HM protects infants against NEC in dose-dependent fashion (2). Whether pasteurized donor human milk protects against NEC is somewhat less certain, although a systematic review came to the conclusion that it does protect significantly (3). The protection that HM affords against sepsis has been well established over the years. A recent study confirmed that HM strongly protects premature babies against late-onset sepsis in dose dependent fashion (4).
The trophic effects of HM are attributed to multiple components that are known to stimulate maturation or otherwise assist in the maturation of the immature gut. When HM is used as a priming agent, these components in the aggregate bring about more rapid maturation of motility and a more rapid decrease in permeability. Clinically trophic effects manifest themselves in lower gastric residual volumes, in more rapid advancement of feedings and in earlier achievement of full feedings (5).
LESS WELL ESTABLISHED ADVANTAGES OF HM
Vohr and coworkers followed a large number of premature infants to 18 and 30 months of age. Increased ingestion of breast milk in the neonatal intensive care unit (NICU) was clearly associated with overall better neurodevelopmental outcomes (6). What makes interpretation of these findings difficult is the presence of confounding factors.
There are some serious disadvantages to the use of HM due to its insufficient nutrient content. The inadequacies of nutrient content make it necessary to provide supplemental nutrients in the form of human milk fortification. Fortification is often not performed adequately for various reasons. This leads to growth retardation, which is associated with impaired neurodevelopment. The prevention of growth retardation is at all times of great importance. But after the first 3–4 weeks of life, when the advantages of HM are no longer as strong as they are earlier, the prevention of growth failure becomes an absolute necessity. Every effort, including the use of formula, is justified to protect the infant from growth failure and the neurodevelopmental impairment it engenders.
The advantages of HM for the premature infant are overwhelming so that every effort must be made to secure HM for all premature infants. At the same time strong efforts must be made to improve fortification of HM.
1. Schanler RJ, Shulman RJ, Lau C, et al. Feeding strategies for premature infants: randomized trial of gastrointestinal priming and tube-feeding method. Pediatrics
2. Meinzen-Derr J, Poindexter B, Wrage L, et al. for the NICHHD Neonatal Research Network. Role of human milk in extremely low birth weight infants’ risk of necrotizing enterocolitis or death. J Perinatol
3. Chauhan M, Henderson G, McGuire W. Enteral feeding for very low birth weight infants: reducing the risk of necrotizing enterocolitis. Arch Dis Child Fetal Neonatal Ed
4. Patel AL, Johnson TJ, Engstrom JL, et al. Impact of early human milk on sepsis and health-care costs in very low birth weight infants. J Perinatol
2013; Jan 2013:1-6.
5. Tyson JA, Kennedy KA. Trophic feedings for parenterally fed infants (Review). Cochrane Database System Rev
6. Vohr BR, Poindexter BB, Dusick AM, et al. Persistent beneficial effects of breast milk ingested in the neonatal intensive care unit on outcomes of extremely low birth weight infants at 30 months. Pediatrics