Protecting Developing Brains with Human Milk

 

The concept of the “neuro NICU” came about around the time that hypothermia for hypoxic ischemic encephalopathy (HIE) came into general practice. These babies have a high likelihood of brain damage, and while cooling (hypothermia) has been shown to improve outcomes, it is apparent that we need to do as much as possible to aid in brain protection and recovery.

Long before this, though, we knew that the concepts of developmental care were important to support the brain development that continues to happen in the NICU, particularly in the very preterm infant.

Even a full term infant has a lot of brain development still happening at a rapid rate. In fact, follow up for high risk and premature infants is important as the evaluation of neurodevelopmental outcome and what measures might be needed to improve the infant’s potential can be determined. Most research done in the NICU evaluates neurodevelopment as a long-term outcome. This is usually evaluated at two years, or even later, to see effects that might not be evident at two years but would be important for growing children and adults. Luckily, brain development and even recovery, in some cases, continues into adulthood!

Many of the care measures that are important in a neuro NICU are important to all infants. Measures included in most neuro NICUs are special diagnostic and monitoring equipment that may help care providers pinpoint the most appropriate time and method to intervene.

Human milk as part of developmental care

Another measure that is part of developmental care includes knowing the most appropriate stimulation to aid and protect brain development. One other not-to-be overlooked measure that can protect and enhance neurodevelopment is mother’s own milk (MOM). The importance of MOM in providing protection against necrotizing enterocolitis and feeding intolerance has been well accepted. However, studies show a positive effect of MOM on neurodevelopmental outcome as well.

One study looked retrospectively at the “dose” of human milk that infants received and compared this to their neurodevelopmental outcomes at 20 months.1 This group observed that the effect is dose dependent, and resulted in a higher Bayley Mental Development Index for every 10 mL/kg/ day of breast milk received. In the group at the highest intake of human milk, at 110 ml/kg/day, a resulting 5-point increase in IQ was observed – a significant increase in practical terms. This group did not mention the use of donor milk, but during the time period studied, donor milk use was not common.

Another study followed 180 infants born at less than 30 weeks or 1250 gms birth-weight. These infants were followed until they were 7 years of age.2 This group found a positive association between the number of days an infant received more than 50% of their feeding as breast milk and improved IQ, academic achievement, working memory, and motor function at 7 years of age. There was no donor milk use in this setting, so all human milk received was MOM.

A study from Chicago, including an ethnically diverse population, sought to determine if there was a difference in outcome in spite of differences in ethnicity and possibly income levels.3 This group also found a significant increase in cognitive IQ with increases for every 10 mL/kg/day increase in human milk received. Donor milk was not used in this population either. MOM was fortified with a bovine-based fortifier and supplementation, and when needed, premature infant formula.

Finally, a single-center study with 27 and 25 infants in each group compared outcomes in infants fed sole MOM diets or MOM supplemented with preterm formula or donor milk.4 This study found a significant difference in cognitive outcomes at both 1 year and 2 years in the infants fed a diet of only donor milk or MOM supplemented with greater than 50% donor milk, with improved outcomes in infants fed sole MOM or MOM supplemented with less than 50% donor milk.

While all of these studies show a difference in infants fed MOM, the last one is noteworthy as more and more NICUs move toward the use of donor milk. While there are certainly benefits to the use of donor milk over a preterm infant formula diet, we can’t lose sight of the fact that there appear to be important differences between MOM and donor milk.

Additional research is ongoing, comparing outcomes in infants who receive MOM, preterm formula, and/or donor milk. Given the research that is currently available, all efforts should focus on supporting mothers to provide sufficient milk for their own infant.

 

References:

1. Vohr, B. R., Poindexter, B. B., Dusick, A. M., McKinley, L. T., Wright, L. L., Langer, J. C., & Poole, W. K. (2006). Beneficial effects of breast milk in the neonatal intensive care unit on the developmental outcome of extremely low birth weight infants at 18 months of age. Pediatrics, 118(1), e115-e123.
2. Belfort, M. B., Anderson, P. J., Nowak, V. A., Lee, K. J., Molesworth, C., Thompson, D. K., … & Inder, T. E. (2016). Breast milk feeding, brain development, and neurocognitive outcomes: a 7-year longitudinal study in infants born at less than 30 weeks’ gestation. The Journal of pediatrics, 177, 133-139.
3. Patra, K., Hamilton, M., Johnson, T. J., Greene, M., Dabrowski, E., Meier, P. P., & Patel, A. L. (2017). NICU Human Milk Dose and 20-Month Neurodevelopmental Outcome in Very Low Birth Weight Infants. Neonatology, 112(4), 330-336.

Madore, L. S., Bora, S., Erdei, C., Jumani, T., Dengos, A. R., & Sen, S. (2017). Effects of Donor Breastmilk Feeding on Growth and Early Neurodevelopmental Outcomes in Preterm Infants: An Observational Study. Clinical Therapeutics.