504 - Effect of Using Liquid Human Milk Fortifiers on Macronutrient Delivery of Human Milk

Poster Number: 504
Publication Number: 504.2281

Background: When using continuous feeds for premature infants, current evidence suggests that a significant amount of fat is lost because of tubing adsorption. Human milk fortified with powdered human milk fortifiers (HMF) also show evidence of further macronutrient loss due to precipitation of HMF. Liquid HMF has predominantly replaced powdered HMF. However, it is not known if liquid HMFs have similar macronutrient loss problems.

Objective: The objective of this study was to evaluate the stability of liquid HMFs after mixing with milk by comparing macronutrient levels in predelivery prepared fortified human milk to the delivered milk.

Design/Methods: This was an in vitro study. Two commercial bovine HMFs, HMF1 and HMF2, were compared. The method of preparing and delivering fortified human milk included preparing a small extra volume that would be used for priming the connection tubes. The Syringe was positioned with tip pointing upwards, figure1. At the end of a 3-hour infusion, prepared milk was compared to delivered milk and to leftover tubing milk. Miris human milk analyzer was used to measure the level of macronutrients across the samples. Paired T-test comparisons were done to evaluate the effect HMF type on macronutrient content across samples. Comparisons were also done to evaluate milk type, donor vs expressed, on macronutrient content across milk samples. Based on our previous study, a sample size of 20 was used, 10 donor and 10 expressed.

Results: Between the two HMFs, the content of fat in delivered milk was similar to that of prepared milk, p>0.05. There was no difference in protein delivery when HMF1 was used. However, HMF2 was associated with an average of 10% higher protein content in delivered milk, p< 0.05. Evaluating the effect of milk type, HMF1 was noted to deliver a higher fat content when mixed with donor milk. HMF1 delivered less fat when mixed with expressed human milk. HMF2 was stable across both milk types; figure 2. Both HMFs behaved differently with regards to protein content. HMF1 was associated with higher protein content in leftover milk independent of milk type. HMF2 was associated with higher protein delivery independent of milk type, figure 3.

Conclusion(s): In continuous feeds, liquid HMFs don’t show consistent macronutrient delivery. There is likely a difference between individual HMF types. Furthermore, there may be an interaction between an individual HMF and the milk type, donor vs expressed, with one HMF type seeming to perform better with one milk type. These findings will need to be further evaluated in future studies.