Lactational Stage of Pasteurized Human Donor Milk Contributes to Nutrient Limitations for Infants.

BACKGROUND: Mother's own milk is the first choice for feeding preterm infants, but when not available, pasteurized human donor milk (PDM) is often used. Infants fed PDM have difficulties maintaining appropriate growth velocities. To assess the most basic elements of nutrition, we tested the hypotheses that fatty acid and amino acid composition of PDM is highly variable and standard pooling practices attenuate variability; however, total nutrients may be limiting without supplementation due to late lactational stage of the milk. METHODS: A prospective cross-sectional sampling of milk was obtained from five donor milk banks located in Ohio, Michigan, Colorado, Texas-Ft Worth, and California. Milk samples were collected after Institutional Review Board (#07-0035) approval and informed consent. Fatty acid and amino acid contents were measured in milk from individual donors and donor pools (pooled per Human Milk Banking Association of North America guidelines). Statistical comparisons were performed using Kruskal-Wallis, Spearman's, or Multivariate Regression analyses with center as the fixed factor and lactational stage as co-variate. RESULTS: Ten of the fourteen fatty acids and seventeen of the nineteen amino acids analyzed differed across Banks in the individual milk samples. Pooling minimized these differences in amino acid and fatty acid contents. Concentrations of lysine and docosahexaenoic acid (DHA) were not different across Banks, but concentrations were low compared to recommended levels. CONCLUSIONS: Individual donor milk fatty acid and amino acid contents are highly variable. Standardized pooling practice reduces this variability. Lysine and DHA concentrations were consistently low across geographic regions in North America due to lactational stage of the milk, and thus not adequately addressed by pooling. Targeted supplementation is needed to optimize PDM, especially for the preterm or volume restricted infant.

Randomized controlled trial of docosahexaenoic acid supplementation in midwestern U.S. human milk donors.

BACKGROUND: Docosahexaenoic acid (DHA) is a long-chain polyunsaturated fatty acid important for neonatal neurodevelopment and immune homeostasis. Preterm infants fed donor milk from a Midwestern source receive only 20% of the intrauterine accretion of DHA. We tested the hypothesis that DHA supplementation of donor mothers would provide preterm infants with DHA intake equivalent to fetal accretion. SUBJECTS AND METHODS: After Institutional Review Board approval and informed consent, human milk donors to the Mother's Milk Bank of Ohio were randomized to receive 1 g of DHA (Martek(®) [now DSM Nutritional Lipids, Columbia, MD]) or placebo soy oil. Dietary intake data were collected and analyzed by a registered dietitian. Fatty acids were measured by gas chromatography/flame ionization detection. Statistical analysis used linear mixed models. RESULTS: Twenty-one mothers were randomly assigned to either the DHA group (n=10) or the placebo group (n=11). Donor age was a median of 31 years in both groups with a mean lactational stage of 19 weeks. Dietary intake of DHA at baseline in both groups was a median of 23 mg/day (range, 0-194 mg), significantly (p<0.0001) less than the minimum recommended intake of 200 mg/day. The DHA content of milk increased in the DHA-supplemented group (p<0.05). CONCLUSIONS: The women enrolled in this study had low dietary DHA intake. Supplementation with preformed DHA at 1 g/day resulted in increased DHA concentrations in the donor milk with no adverse outcomes. Infants fed donor milk from supplemented women receive dietary DHA levels that closely mimic normal intrauterine accretion during the third trimester.

Docosahexaenoic Acid and Amino Acid Contents in Pasteurized Donor Milk are Low for Preterm Infants.

OBJECTIVE: To evaluate whether pasteurized donor human milk meets the nutritional needs of preterm infants in terms of free fatty acid and amino acid contents. STUDY DESIGN: Milk samples were prospectively collected from 39 donors to the Mothers' Milk Bank of Ohio. The fatty acid and amino acid compositions in donor milk samples were measured before and after pasteurization, and values were compared with previously published findings and preterm infant nutrition guidelines. The nutritional adequacy of donor milk for preterm infants was based on estimated daily intake of 150 mL/kg. Statistical significance was adjusted to account for multiple comparisons. RESULTS: Pasteurization did not appreciably affect donor milk composition. Docosahexaenoic acid level (0.1 mol wt %), and concentrations of glycine, aspartate, valine, phenylalanine, proline, lysine, arginine, serine, and histidine in donor milk were all significantly lower than previously reported concentrations in milk. CONCLUSIONS: Donor milk is not substantially affected by pasteurization, but has low concentrations of docosahexaenoic acid and amino acids. Targeted nutritional supplementation of human donor milk for feeding preterm infants might be warranted.