Osmolality of fortified donor human milk: An experimental study.

BACKGROUND: We quantify the osmolality of human milk fortified with human milk fortifiers (HMFs), powder infant formulas and protein additives. METHODS: Commercial liquid HMFs and powder infant formulas were added to pasteurized pooled donor human milk in triplicate and stirred. The osmolality of unfortified and fortified human milk at 22, 24, 26, 27, 28, and 30 kcal/oz (0.73, 0.8, 0.87, 0.9, 0.93, and 1 kcal/ml, respectively) was determined using freezing-point depression. RESULTS: The osmolality of fortified human milk associated with energy density in a linear relationship regardless of the fortification strategies. Multiple liquid HMFs and every powder infant formula exceeded the osmolality threshold of 450 mOsm/kg H2 O within the energy densities tested. CONCLUSION: The osmolality of fortified human milk is highly variable and should be considered when selecting a fortifying agent for human milk.

Displacement of human milk during fortification: An experimental study.

BACKGROUND: This study quantified the displacement of human milk by commercial human milk fortifiers (HMFs) and infant formulas. METHODS: Commercial liquid HMFs and powder infant formulas were added to pasteurized pooled donor human milk in triplicate, stirred, and weighed. The difference in weight between unfortified and fortified human milk at 22, 24, 26, 27, 28, and 30 kcal/ounce was calculated. RESULTS: The displacement of human milk by liquid HMFs and powder infant formulas and powder HMF was highly associated with energy density. A human milk-derived HMF displaced significantly more human milk when compared with bovine milk-derived HMFs at equivalent energy densities. Similarly, powder infant formulas displaced less human milk when compared with a powder HMF, and the addition of hydrolyzed powder infant formulas resulted in less human milk displacement when compared with nonhydrolyzed powder infant formulas. CONCLUSIONS: The displacement of human milk by commercial liquid HMFs and infant formulas must be considered when selecting a fortifying strategy.

Acid/base balance in fortified donor human milk: An experimental study.

BACKGROUND: Our goal was to quantify the pH and total acidity of human milk fortified with human milk fortifiers (HMFs), powder infant formulas, and protein additives. METHODS: Commercial liquid HMFs and powder infant formulas were added to pasteurized pooled donor human milk in triplicate and stirred. The pH of unfortified and fortified human milk at 22, 24, 26, 27, 28, and 30 kcal/ounce (624, 680, 737, 765, 794, and 850 kcal/g, respectively) was determined using a pH meter. Phenolphthalein acidity at 24 and 30 kcal/ounce (680 and 850 kcal/g, respectively) was determined using diluted sodium hydroxide. RESULTS: The pH of unfortified human milk increased within the first hour (6.52 ± 0.06 vs 6.62 ± 0.05, P < 0.0001). Changes in pH largely correlated with caloric density; however, directional changes varied considerably between HMFs and powder infant formulas. Two liquid HMFs demonstrated modest reductions in pH with increasing caloric density whereas one liquid HMF alkalinized human milk with increasing caloric density (analysis of variance P < 0.0001). Phenolphthalein acidity was significantly higher for five HMFs and lower for one HMF at 30 kcal/ounce (850 kcal/g) but not 24 kcal/ounce (680 kcal/g). Powder infant formulas generally increased pH with increasing caloric density (analysis of variance P < 0.0001), but no differences in phenolphthalein acidity were noted. CONCLUSION: Changes in acid/base balancefor fortified human milk are variable and may be a consideration when selecting a fortifying agent for human milk.