Short communication: Effect of refrigerated storage on the pH and bacterial content of pasteurized human donor milk.

Once pasteurized donor milk is thawed for its administration to a preterm or sick neonate, and until it is administered, it is kept refrigerated at 4 to 6°C for 24 h. After this time, unconsumed milk is discarded. This time has not been extended, primarily because of the concern of bacterial contamination. The aim of this study was to determine the changes in pH and bacterial count when pasteurized donor milk was kept under refrigeration for a prolonged period (14 d). In this prospective study, 30 samples of pasteurized donor milk from 18 donors were analyzed. Milk was handled following the regular operating protocols established in the neonatal unit and was kept refrigerated after thawing. pH measurements and bacteriology (on blood agar and MacConkey agar plates) were performed on each sample at time 0 (immediately after thawing) and then every day for 14 d. Changes in pH of samples over time were evaluated with linear mixed-effects regression models. A slow but gradual increase in milk pH was observed starting from the first day [mean (±SD) pH of 7.30 (±0.18) at time 0 and 7.69 (±0.2) on d 14]. No bacterial growth was observed in any of the samples throughout the complete trial except in one sample, in which Bacillus flexus was isolated. In conclusion, pasteurized human donor milk maintains its microbiological quality when properly handled and refrigerated (4-6°C). The slight and continuous increase in milk pH after the first day could be due to changes in the solubility of calcium and phosphate during refrigerated storage.

A longitudinal study of human milk composition in the second year postpartum: implications for human milk banking.

While the composition of human milk has been studied extensively in the first year of lactation, there is a paucity of data regarding human milk composition beyond one year postpartum. Policies vary at milk banks around the world regarding how long lactating women are eligible to donate their milk. The primary purpose of this study is to describe longitudinal changes in human milk composition in the second year postpartum to support the development of evidence based guidelines regarding how long lactating women can donate human milk to a milk bank. Nineteen lactating women in North Carolina provided monthly milk samples from 11 months to 17 months postpartum (N = 131), and two non-profit milk banks provided (N = 33) pooled, unpasteurized milk samples from 51 approved donors less than one year postpartum. There was a significant increase (P < 0.05) in the concentration of total protein, lactoferrin, lysozyme, Immunoglobulin A, oligosaccharides and sodium in longitudinal samples of mother's milk between 11 and 17 months postpartum, while zinc and calcium concentrations declined, and no changes were observed in lactose, fat, iron and potassium. Human milk in the second year postpartum contained significantly higher concentrations of total protein, lactoferrin, lysozyme and Immunoglobulin A, than milk bank samples, and significantly lower concentrations of zinc, calcium, iron and oligosaccharides. Accepting milk bank donations beyond one year postpartum is a potential strategy for increasing the supply of donor milk, but may require mineral fortification.

Effect of Donated Premature Milk in the Prevention of Bronchopulmonary Dysplasia.

INTRODUCTION: Breastfeeding is one of the strategies that has been shown to be effective in preventing severe forms of bronchopulmonary dysplasia (BPD). When mother's own milk (MOM) is not available, pasteurized donor milk (DM) is the best alternative. However, the evidence is inconclusive on the difference in the incidence of bronchopulmonary dysplasia (BPD) between patients fed MOM and those fed with DM. As standard DM is usually mature pooled milk donated by mothers who have delivered their babies at term, the potential benefits of preterm milk may be lost. MATERIALS AND METHODS: An observational, retrospective, single-center study was conducted in the neonatology department of a high-complexity hospital. The study included newborns <32 weeks of gestational age born between January 2020 and December 2022. When supplemental milk was needed, non-pooled preterm pasteurized donor milk (PDM) matched for gestational age and moment of lactation was used in this study, classifying preterm infants in two groups: mainly MOM (>50% of the milk) or mainly PDM (>50% of the milk). Two groups were established: those who received >50% MOM and those who received >50% PDM. They were also classified according to the diagnosis of DBP: one group included no BPD or grade 1 BPD (noBPD/1), while the other included grade 2 or 3 BPD (BPD 2-3). The objectives of this study were, firstly, to evaluate the incidence of BPD 2-3 among patients who predominantly received PDM versus MOM. Secondly, to analyze differences in the type of human milk received and its nutritional components, as well as to study the growth in patients with or without BPD. RESULTS: One hundred ninety-nine patients were included in the study. A comparison of noBPD/1 versus BPD 2-3 groups between those receiving mainly MOM versus PDM showed no significant differences (19% vs. 20%, p 0.95). PDM colostrum in BPD 2-3 compared to noBPD/1 was higher in protein content (2.24 g/100 mL (SD 0.37) vs. 2.02 g/100 mL (SD 0.29) p < 0.01), although the statistical significance decreased after adjustment for gestational age and birth weight z-score (OR 3.53 (0.86-14.51)). No differences were found in the macronutrients in the mature milk of patients feeding more than 50% PDM in both study groups. Growth of BPD 2-3 showed a greater decrease in the difference in z-scores for height at birth and at discharge compared to noBPD/1 (-1.64 vs. -0.43, p 0.03). CONCLUSIONS: The use of mainly MOM or PDM demonstrates a similar incidence of noBPD/1 or BPD 2-3. Non-pooled and matched by gestational age and time of lactation preterm donor milk can probably be an alternative when mother's own milk is not available, with a similar protective effect in the prevention of severe BPD.

Enteral Nutrition: The Intricacies of Human Milk from the Immune System to the Microbiome.

In 2012, the American Academy of Pediatrics stated that all preterm infant diets should consist of human milk (mother's own milk or pasteurized donor human milk). The clinical reasons supporting this policy are many, including reducing infections and retinopathy of prematurity, decreased neonatal intensive care unit length of stay, subsequent readmissions, a decrease in mortality, and improved neurodevelopmental outcomes. This article focuses on human milk, its composition and bioactive factors, and how it affects the gut-brain axis through the microbiome. We examine how differences between mother's own milk and pasteurized donor human milk affect the premature infant.

Factors Associated with the Use of Pasteurized Donor Milk for Healthy Newborns: Experience from the First Human Milk Bank in Vietnam.

BACKGROUND: Pasteurized donor milk (PDM) is typically prescribed to preterm or low birthweight newborns when their mother's own milk is unavailable. In surplus, PDM is prescribed to meet the nutritional needs of healthy newborns in the first few days of life. However, its overuse can undermine efforts to promote and support breastfeeding, waste resources, and reduce the availability of PDM for at-risk newborns. We conducted this study to examine factors associated with the prescription and prolonged use (>48 h) of privately purchased PDM to healthy newborns. METHODS: Prospective observational study of 2440 mothers of healthy, term, and normal birthweight newborns born at Da Nang Hospital for Women and Children between April and August 2019. In addition to the descriptive analysis, we performed multiple logistic regressions to examine factors associated with the prescription of PDM (n = 2440) and prolonged PDM use among those who used PDM (n = 566). RESULTS: Twenty-three percent (566/2440) of healthy, term, and birthweight ≥2500 g newborns received PDM and were included in the study. The prevalence of PDM use was higher for cesarean births (OR: 2.05; 95% CI: 1.66, 2.55) and among male newborns (OR: 1.33; 95% CI: 1.09, 1.62), but lower for farmers or workers (vs. other jobs; OR: 0.71; 95% CI: 0.54, 0.93), family income <10 million VND (vs. ≥10 million VND; OR: 0.67; 95% CI: 0.55, 0.82), and duration of skin-to-skin ≥90 min (vs. <90 min; OR: 0.54; 95% CI: 0.39, 0.76). Prolonged PDM use (12.4% of 566 newborns who used PDM) was associated with the mother having a higher socioeconomic status job (professional, small trader or homemaker; OR: 4.00; 95% CI: 1.39, 12.5), being a first-time mother (OR: 3.39; 95% CI: 1.92, 6.01) or having a cesarean birth (OR: 2.09; 95% CI: 1.02, 4.28). CONCLUSIONS: The prescription and prolonged use of privately purchased PDM was associated with non-medical factors unrelated to the ability to breastfeed effectively. The findings suggest the need for improved breastfeeding communication, counseling and support skills for health staff, development, and application of strict criteria on PDM use for healthy newborns and better routine monitoring of PDM use over time.