Extrauterine Growth Restriction: What Is the Evidence for Better Nutritional Practices in the Neonatal Intensive Care Unit?



NAINR. 2014;14(3):92-98. 

In This Article

Human Milk Fortification

Even though human milk is recommended as the gold standard for enteral feedings in the premature infant, the protein, fat and mineral content of human milk does not meet the nutritional needs of the growing premature infant. In order to meet these needs, fortification is necessary.

Kuschel and Harding[38] conducted a systematic review of 13 RCTs that evaluated human milk fortification versus no fortification. The meta-analysis of the data showed human milk fortification with a multi-component fortifier improves linear and head growth along with short-term weight gain. The use of a fortifier was also found to have no adverse effects and may possibly improve bone formation in premature infants.

Recent findings regarding the use of early amino acids, discussed earlier in this article, lead researchers to explore the addition of protein to enteral feedings as a means to improve growth in small premature infants. In a 2010 systematic review, Premji et al.[39] reviewed five RCTs that examined lower enteral protein intake (< 3 g kg−1 day−1) versus higher protein intake (> 3 g kg−1 day−1). Higher enteral protein intake at 3–4 g kg−1 day−1 resulted in improved weight gain and an increase in nitrogen accretion. Evidence presented in these systematic reviews support human milk fortification with added protein, fat, and mineral intake in order to meet the unique nutritional needs of the premature infant and to promote adequate growth in smaller premature infants.

Miller et al.[40] confirms the systematic review findings in a more recent RCT of 92 preterm infants who either received human milk fortified with 1.4 g of protein/100 ml or the standard human milk fortifier with 1 g of protein/100 ml. The infants who received the human milk fortifier with added protein had significantly better weight gain at the end of the study. In a secondary analysis, the infants who received the higher protein human milk fortifier were less likely to be at the 10th percentile for length. The authors of the study concluded that a human milk fortifier with added protein is needed to promote adequate growth in premature infants.

Human milk fortification traditionally has been accomplished through the use of bovine-based powdered human milk fortifiers. Bovine-based powdered human milk fortifiers have been predominantly manufactured by two different infant nutrition companies, Abbott Nutrition® and Mead Johnson Nutrition®. The nutritional composition of both products is similar but some distinct differences do exist (Table 2). Similac® human milk fortifier[41] has more carbohydrate but less fat content and higher levels of calcium and phosphorus. Enfamil® human milk fortifier[42] has slightly more protein, more fat content with less carbohydrate and significantly more iron. No RCTs have been conducted to determine which bovine-based powdered human milk fortifier provides a better nutrient content for premature infants. However, it has been reported that the iron content of Enfamil® human milk fortifier decreases the bacteriostatic properties of human milk.[43]