In the United States, for nurses who work in the neonatal intensive care unit (NICU), routine fortification of human milk for NICU infants has become standard of care. This routine fortification of human milk can lead mothers to question why their milk is "not good enough for their infant." Nurses may also question why if human milk is the ideal form of nutrition for all infants, what is the harm in adding other substances to human milk? In the United States, there are human milk fortifiers made from bovine milk as well as from human milk (Spatz, Schmidt, & Kinzler, 2014).

In May 2016, the Cochrane database released their updated meta-analysis about routine multinutrient fortification for preterm infants (Brown, Embleton, Harding & McGuire, 2016). They examined 14 trials with a total of 1,071 infant participants (Brown et al.). The trials were generally small and had weak methodology. The data were synthesized using risk ratios, risk differences, and mean differences (MDs). The meta-analysis reports there is low-quality evidence that multinutrient fortification increases in-hospital rates of growth (MD 1.81 g/kg/day, 95% confidence interval [CI] 1.23-2.40), length (MD 0.12 cm/week, 95% CI 0.07-0.17), and head circumference (MD 0.08 cm/week, 95% CI 0.04-0.12) (Brown et al.). The data suggested that any increases noted in infant growth and development applied to the initial NICU hospitalization only. In many NICUs, the expectation is that infants gain 15 to 30 g/day. It is evident from the meta-analysis that adding fortifiers to milk is not solving the concern of weight gain. One must question if the small gains in head circumference and length are clinically significant.

Brown et al. (2016) further conclude that the research does not provide strong evidence that feeding preterm infants with multinutrient fortified human milk compared with unfortified human milk affects important outcomes such as longer-term weight gain or development. There are very limited data available for growth and developmental outcomes that have been assessed beyond infancy, and these studies found no effects of fortification (Brown et al.).

Worldwide, fortification of human milk in the NICU is not routine. Given that not all countries fortify and with the evidence found in this new systematic review, we must question our clinical practice. For nurses to make good clinical judgment about feeding human milk, understanding the science of daily variation in caloric density of milk would be essential. Fat is the most variable component of human milk, so fractionation of milk and understanding a mother's 24-hour milk production will allow us to better optimize mother's own milk in improving growth (Spatz et al., 2014).

Clearly, more high-quality clinical research on optimization of human milk and fortification is warranted. Current evidence is flawed (Brown et al., 2016). Routine fortification of human milk for infants in the NICU may not offer once assumed benefits. This is an excellent opportunity for nurse researchers to develop rigorous studies to make a contribution to finding some of the answers to this important question about NICU babies being fed human milk with multinutrient fortification.

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