The effects of human milk fortification on nutrients and milk properties

Point-of-care human milk concentration by passive osmosis: comprehensive analysis of fresh human milk samples

OBJECTIVE

Preterm infants need enrichment of human milk (HM) for optimal growth. This study evaluated a novel, point-of-care human milk concentration (HMC) process for water removal from fresh HM samples by passive osmotic concentration.

STUDY DESIGN

Nineteen fresh HM samples were concentrated by incubation with the HMC devices for 3 h at 4 °C. Pre- and post-concentration HM samples were compared by HM properties for: pH, osmolality, macronutrients, enzyme activity, bioactive, and total cell viability.

RESULTS

Passive osmotic concentration reduced HM volume by an average of 16.3% ± 3.8% without a significant effect on pH or cell viability. Ten of the 41 HM components did not differ significantly (p > 0.05) between pre- and post-concentration samples. Twenty-three increased within the expected range by volume reduction. Six increased more than expected, two less than expected, and none decreased significantly.

CONCLUSION

Passive osmotic concentration of fresh HM can concentrate HM components by selective removal of water. HM osmolality and pH remained within neonatal feeding parameters.

Human Milk Fortification Strategies in the Neonatal Intensive Care Unit

Multicomponent fortification is the standard of care to support short-term growth in preterm infants receiving human milk. There is no consensus regarding the optimal timing, method, or products used to fortify human milk. Both bovine milk-based and human milk-based human milk fortifiers are safe options, though increased fortification and enrichment may be needed to achieve adequate growth. Additional studies are needed to evaluate newer fortifier products and fortification strategies.

Effect of fortification on the osmolality of human milk

BACKGROUND

It is known that human milk fortifiers (HMF) increases osmolality of human milk (HM) but some aspects of fortification have not been deeply investigated. Our aim was to evaluate the effect of fortification on the osmolality of donor human milk (DHM) and mother's own milk (MOM) over 72 h of storage using two commercial fortifiers and medium-chain triglycerides (MCT) supplementation.

METHODS

Pasteurized DHM and unpasteurized preterm MOM were fortified with 4% PreNAN FM85, 4% PreNAN FM85 plus 2% MCT, or 4% Aptamil BMF. Osmolality was measured in unfortified DHM and MOM and, moreover, just after fortification (T₀), and after 6 (T₆), 24 (T₂₄) and 72 h (T₇₂) to determine the effect of mixing and storage.

RESULTS

Unfortified DHM and MOM did not show changes of osmolality. Fortification increased osmolality of DHM and MOM without changes during the study period, except for Aptamil BMF which increased osmolality of MOM. The addition of MCT to fortified human milk (FHM) did not affect its osmolality.

CONCLUSIONS

Changes of osmolality in the 72 h following fortification of both DHM and MOM did not exceed the safety values supporting the theoretically possibility of preparing 72 h volumes of FHM. Supplementation with MCT of FHM does not change osmolality suggesting that increasing energy intake in preterm infants via this approach is safe.

Human milk pH is associated with fortification, postpartum day, and maternal dietary intake in preterm mother-infant dyads

OBJECTIVE

To compare pH of human milk types (mother's own milk (MOM), pasteurized donor human milk (PDHM), fortified MOM, and fortified PDHM) fed to preterm infants.

STUDY DESIGN

This observational study consisted of 63 mother-infant dyads < 34 weeks gestation. Human milk samples (n = 245), along with maternal factors, were collected for pH analysis. pH of MOM was analyzed over the course of lactation accounting for fortification status, postpartum day, and storage conditions.

RESULTS

Mean pH of MOM was slightly acidic at 6.60 ± 0.28, which was significantly higher (p < 0.05) than other milk types. pH of MOM varied by fortification, postpartum day, and maternal vegetable/fiber intake. There was a significant interaction between fortification status and postpartum day; pH of MOM decreased over time, while pH of fortified MOM increased over time.

CONCLUSION

pH of human milk varied by type. pH of MOM was significantly associated with fortification status, postpartum day, and maternal vegetable/fiber intake.

Do Maternal Factors and Milk Expression Patterns Affect the Composition of Donor Human Milk?

A primary role of Human Milk Banks (HMBs) is to provide human milk (HM) for preterm infants and to support the mothers of these infants as they establish their own milk supply. A better understanding of the variation in the energy and macronutrients contents of donor human milk (DHM) potentiates targeted nutrition for preterm babies. Therefore, the aim of this study was to assess the variability of energy and macronutrients content in DHM and to investigate the impact of maternal factors and feeding practices on the nutritional value of DHM. The study involved 49 donors registered in the HMB in the Holy Family Hospital in Warsaw, Poland. Samples from each donor were pooled within a maximum of two weeks. The composition of DHM, including energy content, protein, fat, and carbohydrate concentrations, was analyzed using the Miris Human Milk Analyzer. The analyses were performed before the pasteurization process. The mean time of milk donation to HMB was 13.2 ± 6.0 weeks. There were no significant differences in energy and macronutrients contents of DHM in the beginning and at the end of milk donation to HMB, however, HM fat concentration was positively correlated with afternoon feedings (r = 0.289, p = 0.044). The method of feeding (breastfeeding vs. feeding only expressed milk) also did not impact the nutritional value of DHM. Future research for the DHM should include a further cross-sectional observational study with the collection of detailed donor information and characteristics of milk expression and feeding practices to further evaluate the pooling processes and the effect on DHM composition.

Early Enteral Feeding in Preterm Infants: A Narrative Review of the Nutritional, Metabolic, and Developmental Benefits

Enteral feeding is the preferred method of nutrient provision for preterm infants. Though parenteral nutrition remains an alternative to provide critical nutrition after preterm delivery, the literature suggests that enteral feeding still confers significant nutritional and non-nutritional benefits. Therefore, the purpose of this narrative review is to summarize health and clinical benefits of early enteral feeding within the first month of life in preterm infants. Likewise, this review also proposes methods to improve enteral delivery in clinical care, including a proposal for decision-making of initiation and advancement of enteral feeding. An extensive literature review assessed enteral studies in preterm infants with subsequent outcomes. The findings support the early initiation and advancement of enteral feeding impact preterm infant health by enhancing micronutrient delivery, promoting intestinal development and maturation, stimulating microbiome development, reducing inflammation, and enhancing brain growth and neurodevelopment. Clinicians must consider these short- and long-term implications when caring for preterm infants.

Comparative effectiveness of liquid human milk fortifiers: A systematic review and meta-analysis

OBJECTIVE

To determine the effectiveness of liquid human milk fortifiers (HMFs) derived from exclusive HM or hydrolyzed protein on growth, necrotizing enterocolitis (NEC), or late-onset sepsis in North American very low-birth-weight (VLBW) infants compared with powder HMFs (control).

METHODS

Prospective trials published between 2009 and 2020 were systematically reviewed, and meta-analysis was conducted by using a random-effects model.

RESULTS

Five studies were identified for up to 591 participants across 39 centers. Study treatments included whey or casein hydrolysate HMF and exclusive HM HMF. Infants fed whey or casein hydrolysate HMF had growth differences compared with the control. No differences were found across treatments in regard to NEC or sepsis.

CONCLUSION

Very low-quality evidence suggests greater linear growth in VLBW infants fed whey hydrolysate liquid HMF, as well as greater weight gain in those fed casein hydrolysate HMF, compared with the control. Additional prospective, multicenter randomized controlled trials are needed to confirm these estimates because of sparsity of evidence. There is insufficient evidence to support HMF decisions regarding NEC or late-onset sepsis prophylaxis.

Quality Assurance in Lactation: Reliability of OM-6050 Station System to Test Mother's Milk Osmolality

BACKGROUND

Mother's own milk does not provide enough nutrients to feed a preterm baby born before 32 weeks' gestation; therefore, human milk fortifiers are needed. However, human milk fortifiers increase the osmolality, and enteral administration of high osmolality fluids has been associated with gastrointestinal symptoms. For this reason, it is necessary for laboratories to have a validated system in order to measure human milk osmolality.

RESEARCH AIM

The aim of this study was to validate the OM-6050 Station System for measuring the osmolality of fortified mother's milk samples.

METHODS

Osmolality was measured using the osmometer OM-6050 Station System. Milk samples from healthy mothers (N = 3) unfortified and with two fortifiers (Almirón Fortifier^® or NAN FM85^®), as well as a nutritional supplement (Duocal MCT^®) were used in the validation study through precision and linearity analysis.

RESULTS

In the precision study the mean intra-assay coefficient of variation was 1.2% and 1.7% for mother's milk and fortified mother's milk, respectively. The mean inter-assay coefficient of variation was ≤ 1% in both cases. In the linearity study the regression analysis had a linear response to fortified mother's milk osmolality between 294 mOsm/kg and 539 mOsm/kg.

CONCLUSION

The osmometer OM-6050 Station was reliable for determining the osmolality of fortified and unfortified mother's milk. It may be useful in the clinical practices within Neonatal Intensive Care Units.

Olfactory Cues in Infant Feeds: Volatile Profiles of Different Milks Fed to Preterm Infants

Background: Smell is determined by odor-active volatile compounds that bind to specific olfactory receptors, allowing us to discriminate different smells. Olfactory stimulation may assist with digestion and metabolism of feeds in the neonate by activation of the cephalic phase response of digestion. Infants' physiological responses to the smell of different milks suggest they can distinguish between breastmilk and infant formula. We aimed to describe the profile of volatile compounds in preterm breastmilk and investigate how this differed from that of other preterm infant feeding options including pasteurized donor breastmilk, breastmilk with bovine milk-based fortifier, human milk-based products and various infant formulas. Methods: Forty-seven milk samples (13 different infant formulas and 34 human milk-based samples) were analyzed. Volatile compounds were extracted using Solid Phase Micro Extraction. Identification and relative quantification were carried out by Gas Chromatography with Mass Spectrometry. Principal Component Analysis (PCA) and one-way Analysis of Variance (ANOVA) with Tukey's HSD (parametric data) or Conover's post-hoc test (non-parametric data) were used as appropriate to explore differences in volatile profiles among milk types. Results: In total, 122 compounds were identified. Breastmilk containing bovine milk-based fortifier presented the highest number of compounds (109) and liquid formula the lowest (70). The profile of volatile compounds varied with 51 compounds significantly different (adjusted p < 0.001) among milk types. PCA explained 47% of variability. Compared to preterm breastmilk, the profile of volatile compounds in breastmilk with added bovine milk-based fortifier was marked by presence of fatty acids and their esters, ketones and aldehydes; infant formulas were characterized by alkyls, aldehydes and furans, and human milk-based products presented high concentrations of aromatic hydrocarbons, terpenoids and specific fatty acids. Conclusions: Sensory-active products of fatty acid oxidation are the major contributors to olfactory cues in infant feeds. Analysis of volatile compounds might be useful for monitoring quality of milk and detection of oxidation products and environmental contaminants. Further research is needed to determine whether these different volatile compounds have biological or physiological effects in nutrition of preterm infants.

Fortification With Bovine Colostrum Enhances Antibacterial Activity of Human Milk

Objectives

Human milk (HM) is the optimal diet for neonates, but it does not provide enough nutrients for preterm infants. HM fortifiers based on highly processed mature bovine milk (BMFs) are routinely used for preterm infants despite risks of causing gut dysfunction and systemic infection. Gently‐processed bovine colostrum as a fortifier (BCF) may better protect against infection and inflammation. We hypothesized that BCF‐fortified HM has enhanced antimicrobial activity against pathogens that commonly cause neonatal sepsis, relative to BMF‐fortified HM.

Methods

Holder‐pasteurized HM samples (10 mothers) were aliquoted into 3 fractions: unfortified HM and HM fortified with either BMF or BCF. The samples were analyzed for pH, lactoferrin concentrations, and antimicrobial activities against Staphylococcus epidermidis, Escherichia coli, and Enterococcus faecalis.

Results

HM+BCF had a lower pH and higher lactoferrin levels than HM+BMF, with HM being intermediate. Relative to infant formula, HM decreased the growth of S epidermidis, E coli, and E faecalis, with no difference between preterm and term HM. Addition of BMF abolished the antimicrobial effect of HM against S epidermidis and E faecalis but not E coli. By contrast, addition of BCF into HM enhanced antimicrobial activity against S epidermidis and E coli, relative to unfortified HM. HM+BCF was superior to HM+BMF in inhibiting growth of all tested bacteria.

Conclusion

BMF fortification decreased whereas BCF fortification enhanced in vitro antimicrobial activity of HM. This effect may partly be derived from the high levels of antimicrobial factors found in BCF, including lactoferrin. BCF may be a better fortifier than BMF for preterm infants.

Growth and Clinical Outcomes of Very Low-Birth-Weight Infants Receiving Acidified vs Nonacidified Liquid Human Milk Fortifiers

BACKGROUND

Liquid human milk fortifiers are used commonly in neonatal intensive care. Use of an acidified HMF (A-HMF) is associated with transient metabolic acidosis, but whether growth outcomes differ between infants fed A-HMF vs nonacidified HMF (NA-HMF) remains unknown.

METHODS

Retrospective cohort study of 255 infants born at <33 weeks' gestation and ≤1500 g who were receiving ≥75% fortified human milk on day of life 14, in a level III neonatal intensive care unit (NICU) from May 2015 to December 2018. Infants born before October 2017 (n = 165) received A-HMF, whereas infants born after October 2017 (n = 90) received NA-HMF. We used logistic regression to estimate odds of metabolic acidosis (serum bicarbonate <16 mEq/L in the first 21 days of life) in infants receiving A-HMF vs NA-HMF and linear mixed models to compare the mean size at discharge (weight, length, head z-scores) by HMF type. We adjusted models for confounders and accounted for the nonindependence of multiple births.

RESULTS

Median gestational age was 28.7 weeks (range, 22.6-32.9) and birth weight 1.1 kg (range, 0.4-1.5). Infants receiving A-HMF had higher adjusted odds of metabolic acidosis than infants receiving NA-HMF (adjusted odds ratio, 2.7; 95% CI, 1.2-6.2). There were no differences between groups in size z-scores at discharge.

CONCLUSIONS

In human-milkfed, very-low-birthweight infants, fortification with liquid A-HMF may contribute to metabolic acidosis in the first month of life, but this practice does not appear to impair growth through NICU discharge, compared with fortification with NA-HMF.

The Nutritional Composition and Energy Content of Donor Human Milk: A Systematic Review

The American Academy of Pediatrics recommends donor human milk (DHM) as the preferred feeding strategy for preterm infants when the milk of the mother is unavailable, based on conclusive evidence of lower rates of necrotizing enterocolitis with DHM feedings compared with preterm infant formula. The nutritional composition of DHM may differ from maternal milk for many reasons including differences in maternal characteristics, milk collection methods, and the impact of donor milk banking practices. The purpose of this systematic review is to examine the literature regarding research on the fat, protein, carbohydrate, vitamin, and mineral composition of DHM obtained through nonprofit milk banks or commercial entities. PubMed, CINAHL, and Scopus databases were searched for articles published between 1985 and 30 April, 2019. In total, 164 abstracts were screened independently by 2 investigators, and 14 studies met all inclusion criteria. Studies were predominantly small (<50 samples) and measured macronutrients. Few studies assessed vitamins and minerals. Information bias was prevalent due to the use of a variety of analytical methods which influence accuracy and cross-study comparisons. Other sources of information bias included missing information regarding methods for protein and calorie assessment. Despite these limitations, existing research suggests the potential for 2-fold and greater differences in the fat, protein, and energy composition of DHM, with mean values for energy and fat often below clinical reference values expected for human milk. Further research is warranted regarding the nutritional composition of DHM, with a prioritization on measuring macronutrients and micronutrients using established reference methods.

Fat and Protein Variability in Donor Human Milk and Associations with Milk Banking Processes

Background: The impact of milk banking processes on macronutrient variability in donor human milk (DHM) is largely unknown. Objective: To gain a better understanding of fat and protein composition in DHM and assess potential relationships with modifiable milk bank processes. Methods: Samples of raw, pooled DHM were collected from 20 milk banks (n = 300) along with the following processing attributes: if macronutrient analysis was used to select donors for pooling (target pooling; yes/no), number of donors per pool, pooling container material (glass/plastic/other), and method for mixing during bottling (manual/mechanical). Fat and protein were assessed. Homoscedasticity was assessed and magnitude of the spread was quantified. Results: Fat ranged from 1.9 to 6.1 g/dL (n = 298) and protein ranged from 0.7 to 1.4 g/dL (n = 300). Variability in fat was significantly lower in samples that had been target pooled (p = 0.04), contained more donors per pool (p < 0.001), and had been mixed mechanically (p < 0.001). Variability in protein was significantly lower in samples that contained more donors per pool (p = 0.001). In a stratified analysis, increasing the number of donors per pool only reduced nutrient variability in samples that were not target pooled. Conclusion: For milk banks that do not target pool, using a greater number of donors in a pool may reduce fat and protein variability.

Fortifier selection and dosage enables control of breast milk osmolarity

BACKGROUND

Human breast milk (BM) fortification is required to feed preterm newborns with less than 32 weeks of gestation. However, addition of fortifiers increases osmolarity and osmolarity values higher than 450 mOsm/kg may be related to gastrointestinal pathology. Hence, fortifier selection and dosage are key to achieve optimal feeding.

OBJECTIVES

To compare the effect on osmolality of adding different fortifications, including recently developed formulations, to BM and to study evolution of osmolarity over time in supplemented BM.

METHODS

Frozen mature BM from 10 healthy mothers of premature newborns was fortified with each of the following human milk fortifiers (HMF): AlmirónFortifier®, NANFM85®, or PreNANFM85®. In addition, fortified BMs were modified with one of the following nutritional supplements (NS): Duocal MCT®, Nutricia® AminoAcids Mix, or Maxijul®. Osmolality of BM alone, fortified and/or supplemented was measured at 1 and 22 hours after their preparation. All samples were kept at 4°C throughout the study.

RESULTS

Osmolality of BM alone was close to 300 mOsm/kg and did not change over 22 hours. When equicaloric amounts of HMF AlmirónFortifier®, NANFM85®, and PreNANFM85® were added to BM, osmolality increased roughly to 480 mOsm/kg with the first two fortifiers and only to 433±6 mOsm/kg with the third one. Upon addition of any of four different NSs to BM modified with AlmirónFortifier® and NANFM85®, osmolality reached values greater than 520 mOsm/kg, while osmolality of PreNANFM85® with two out of the four NSs remained below 490 mOsm/kg. NSs supplementing carbohydrates and hydrolysed proteins resulted into a higher increase of BM osmolarity. Osmolality increased significantly with time and, after 22h, only BM modified with PreNANFM85® remained below 450 mOsm/kg.

CONCLUSIONS

Upon addition of the HMFs tested, BM osmolality increases significantly and keeps raising over time. All HMFs but the recently developed PreNAN FM85® at 4% exceed the AAP recommended threshold for osmolarity of 450 mOsm/kg. Addition of NSs to PreNAN FM85® at 4% significantly increases osmolality above 450 mOsm/Kg. Thus, using PreNAN FM85® at 5% may be preferable to adding nutritional supplements since nutritional recommendations by the ESPGHAN are reached with a lower increase in osmolality.

Effects of human milk fortifier properties on intrinsic probiotic bacteria

Background To meet the nutritional needs of preterm infants, multicomponent nutrient fortifiers are added to human milk. The fortified human milk (FHM) product changes the physical and biochemical characteristics of the milk. We questioned whether such physical-chemical changes in the milk would alter intrinsic probiotic bacterial activity. The objective of the study was to evaluate the effect of osmolality and pH on the growth of probiotic bacterial species intrinsic to human milk. Methods Human milk samples (n = 26) were collected from mothers in the neonatal intensive care unit (NICU) and stored at -20°C until analyzed. The samples were thawed and divided into three portions. Human milk fortifiers (HMFs) were added to two portions to prepare concentrations of FHM. The remaining portion was the unfortified control sample. Each sample was then divided into two parts. One part (baseline) was used to measure the osmolality and pH and plated on selective agar to enumerate the growth of lactobacilli and bifidobacteria species. The remaining part was incubated at 37°C for 24 h to further test bacterial integrity (post-incubation) and then the same measurements were made (osmolality, pH, bacterial colony counts). Results When compared with unfortified milk at baseline, osmolality increased and pH decreased significantly after the addition of HMFs. Lactobacilli and bifidobacteria colony counts did not differ among the groups pre-incubation. Post-incubation lactobacilli and bifidobacteria increased in all the groups. Conclusion The appropriate addition of HMFs differentially affected the osmolality and pH of the milk. These physical changes did not affect the growth of probiotic bacterial species.

Use of acidified versus non-acidified liquid human milk fortifier in very low birth weight infants: A retrospective comparison of clinical outcomes

BACKGROUND

Use of human milk is recommended for low birth weight (VLBW) infants, but must be safety fortified with sterile liquid fortifiers to be nutritionally sufficient. Due to clinical concern for a high incidence of metabolic acidosis among VLBW infants fed human milk fortified with acidified liquid human milk fortifier (ALHMF), we aimed to retrospectively compare the outcomes of infants fed ALHMF to those fortified with non-acidified liquid HMF (NLHMF).

METHODS

Medical records of VLBW neonates admitted to our institution's neonatal intensive care unit from July 1st, 2013 to June 30th, 2014 were reviewed. 129 patients were included in the study, 61 of which received ALHMF and 68 received NLHMF. Metabolic, nutritional and clinical outcomes, including growth, were compared between the two cohorts.

RESULTS

Of the infants who received ALHMF, 70.5% developed metabolic acidosis compared to only 11.8% in the NLHMF group (p < 0.001). In addition, infants who received NLHMF had a 10% greater growth velocity during the period of fortification (p = 0.01). During the full course of hospitalization, no difference in growth velocity was seen between the groups and greater length gains were found in the ALHMF group.

CONCLUSIONS

The use of human milk fortified with ALHMF was associated with an increased incidence of metabolic acidosis and poorer growth during the period of fortification when compared to NLHMF-fortified feedings. These growth effects were not apparent when the duration of hospitalization was considered, suggesting a need for further study to better characterize the advantages and disadvantages of each fortifier.

Bacterial Content of Fortified and Unfortified Holder Pasteurized Donor Human Milk During Prolonged Refrigerated Storage

OBJECTIVE

To assess the microbial growth in unfortified and fortified Holder pasteurized donor human milk (HPDHM) during 96 hours of refrigerated storage in a clinical setting.

METHODS

Thirty-six unfortified samples and 77 fortified samples of HPDHM were prepared in a neonatal intensive care milk preparation room and stored in the NICU refrigerator at 4°C to simulate a real-life feeding environment. One milliliter aliquots were removed at 24-hour intervals and cultured in duplicate for bacterial growth on solid blood agar medium. Viable bacterial colonies were characterized using standard microbiological methods.

RESULTS

96.5% of milk samples manipulated in a vertical laminar flow hood were negative for bacterial growth. In the remainder 3.5% of the samples, the maximum growth was 1 colony forming unit/0.1 ml plated. Higher colony counts were observed when the laminar hood was not used. In all cases, the colonies represented common skin bacteria and demonstrated an inconsistent and unsustained growth. Fortifier status and storage time were not significantly associated with increased bacterial growth (P > 0.05).

CONCLUSIONS

Unfortified and fortified HPDHM remain largely free of bacterial growth for up to 96 hours of refrigerated storage in NICU settings. Sample handling techniques are important for preventing microbial contamination.

The Effects of Fortification and Refrigerated Storage on Bioactive Proteins in Holder-pasteurized Donor Human Milk

OBJECTIVE

The aim of the study was to assess the total protein, lysozyme, and immunoglobulin A (IgA) content of unfortified and fortified Holder-pasteurized donor human milk (HPDHM) during 96 hours of refrigerated storage.

STUDY DESIGN

HPDHM was prepared in a hospital feeding room and subjected to treatment with 3 different fortifiers: an acidic, bovine-based (F-ACID), a neutral, bovine-based, and a human milk-derived (F-HUM) fortifier. Unfortified HPDHM served as the control (CONTROL). Samples were stored at 4°C, and every 24 hours, a 1-mL aliquot was removed for analysis.

RESULTS

At baseline, there was a significant difference in protein (mean, standard deviation) concentration (g/dL) between control (1.3, 0.1) and all other treatments (F-ACID = 2.0, 0.2; neutral, bovine-derived fortifier = 2.2, 0.1; F-HUM = 2.5, 0.1; P < 0.001). Lysozyme and IgA were significantly lower in the F-ACID group (P < 0.001). Lysozyme and IgA were significantly higher in the F-HUM group (P < 0.001). There was no significant effect of storage time (P > 0.9) for all dependent variables.

CONCLUSION

The type of fortifier has a more significant impact on bioactive components in fortified HPDHM than does storage time. Our findings of lack of negative impact of refrigeration storage time on the protein and bioactive components of donor milk strengthen the recent recommendations to extend storage time to 48 hours.

Effects of Nutrition Supplementation on Osmolality of Expressed Human Milk

BACKGROUND

Provision of human milk to premature infants optimizes outcomes, but it must be supplemented to meet their nutrient and caloric requirements for growth. Our objective was to quantify the osmolality of human milk mixed with commercially available human milk fortifiers (HMF) and powdered infant formula, as currently fed to premature infants, simulating standard neonatal intensive care unit feeding practices for mixing and refrigerator storage.

METHODS

Expressed human milk (EHM) samples obtained from mothers of premature infants (≤32 weeks gestation) were mixed with standard commercial products, and osmolalities were quantified.

RESULTS

HMF significantly increased the micronutrient content and osmolality of EHM. Osmolalities were 291 ± 6 mOsm/kg (mean ± SD) for unsupplemented milk, and 505 ± 5 and 315 ± 19 mOsm/kg after supplementation to 24 kcal/oz using 2 current U.S. Liquid EHM fortifiers. When using powdered infant formulas to further increase the caloric content of fortified EHM >24 kcal/oz, osmolalities increased by 10.5-23.0 mOsm/kg for each additional kcal/oz. The use of powdered formulas alone (without HMF) increased osmolality without comparable increases in nutrient content. Refrigeration for 24 hours did not affect osmolalites.

CONCLUSION

Our finding that several common feeding formulations exceed 450 mOsm/kg, and the lack of evidence of adverse effect, raise the question of whether current maximum osmolality guidelines should be reevaluated to enable optimal nutrition for infants in neonatal intensive care.

Human milk enriched with human milk lyophilisate for feeding very low birth weight preterm infants: A preclinical experimental study focusing on fatty acid profile

BACKGROUND

Human milk, with essential nutrients and long chain polyunsaturated fatty acids (LC-PUFAs) such as the omega 3 and 6 fatty acids is important for development of the central nervous system and the retina in very low birth weight infants (<1,500 g). However, breast milk may not be sufficient to meet these needs. The possibility of supplementing breast milk with a lyophilisate of human milk was explored in this study. The objectives of this study were to determine the total lipid content and the lipid profile of the Human Milk on Baseline (HMB) and that of the Concentrates with the Human Milk + lyophilisate (with lyophilisate of milk in the immediate period (HMCI), at 3 months (HMC3m), and at 6 months (HMC6m) of storage).

METHODS

Fifty donors from the Human Milk Bank of Children's Hospital provided consent, and donated milk samples. Macronutrient (including total lipids) quantification was performed using the MIRIS® Human Milk Analyzer, and the fatty acid profile was determined by gas chromatography (CG-FID, SHIMADZU®).

RESULTS

There was a higher lipid concentration in HMCI relative to HMB. The concentrations of the main fatty acids (% of total) were as follows: palmitic acid (C16:0) HMB, 22.30%; HMCI, 21.46%; HMC3m, 21.54%; and HMC6m, 21.95% (p<0.01); oleic acid (C18:1n-9) HMB, 30.41%; HMCI, 30.47%; HMC3m, 30.55%; and HMC6m, 29.79% (p = 0.46); linoleic acid (C18:2n-6) HMB, 19.62%; HMCI, 19.88%; HMC3m, 19.49%; and HMC6m, 19.45% (p = 0.58); arachidonic acid (C20:4n-6) HMB, 0.35%; HMCI, 0.16%; HMC3m, 0.13%; and HMC6m, 0.15% (p<0.01); α-linolenic acid (C18:3n-3) HMB,1.32%; HMCI, 1.37%; HMC3m, 1.34%; and 1.34% HMC6m (p = 0.14); docosahexaenoic acid (C22:6n-3) HMB, 0.10%; HMCI, 0.06%; HMC3m, 0.05%; and HMC6m, 0.06% (p<0.01). There were no significant changes in the lipid profile when stored. There was no evidence of peroxidation during storage.

CONCLUSIONS

Freeze-dried human milk fortified with a human milk concentrate brings potential benefits to newborns, mainly by preserving the essential nutrients present only in breast milk; however, further clinical studies are required to evaluate the safety and efficacy of the concentrate as a standard nutritional food option for very low birth weight infants.

Osmolality of a fortified human preterm milk: The effect of fortifier dosage, gestational age, lactation stage, and hospital practices

OBJECTIVE

The purpose of this study was to evaluate the dose-dependent effect of human milk fortifier (HMF) on the osmolality of various preterm human milks (PHMs) at different gestational and lactation stages, and with different storage and treatment conditions that are routinely used in neonatal intensive care units (NICUs).

STUDY DESIGN

Twenty-four mothers who had given birth to their baby before 28 or between 29 and 31 weeks of pregnancy participated in the study after 1-2 weeks or 3-4 weeks breastfeeding after delivery. The study was a prospective, multicenter, comparative, and noninterventional study. Osmolality of fresh or pasteurized human milk stored at 4°C was measured (cryoscopy) at baseline, and 24hours after adding Suppletine^® Human Milk fortifier (SHMF) at 3%, 4%, 4.5%, and 5% (w/v).

RESULTS

PHM without supplementation had an osmolality (mean±SD) of 301±8 mOsm/kgH₂O (n=40; 95% CI: [298; 303]). Adding 3-5% SHMF induced a linear increase of osmolality (P<0.001; r²=0.975). With 4% SHMF, the osmolality measure was 443±13mOsm/kg H₂O (95% CI: [439-447]). Neither a 24-hour storage at 4°C nor pasteurization induced a modification of osmolality compared to the fresh samples.

CONCLUSION

Whatever the origin and quality of milk as well as hospital practices, adding up to 4% (w/v) SHMF to PHM increases its nutritional quality and osmolality without exceeding 450mOsm/kgH₂O, which is generally recognized as safe.

Effects of Refrigerated and Frozen Storage on Holder-Pasteurized Donor Human Milk: A Systematic Review

BACKGROUND

Pasteurized donor human milk (PDHM) is the recommended feeding alternative for preterm infants when mother's own milk is not available. Use of PDHM in United States neonatal hospitals is increasing, although guidelines for the refrigerated and frozen storage are limited.

OBJECTIVE

We aimed to review the current evidence for the storage of Holder PDHM (HPDHM) under refrigerated and frozen storage conditions.

METHODS

A systematic review of the literature was conducted for studies published between 1985 and May 2018. Studies were included if they studied the storage of Holder-pasteurized human milk under refrigerated or frozen storage conditions.

RESULTS

Fourteen studies met the inclusion criteria. Five studies addressed refrigerated storage and nine studies addressed frozen storage. There was little overlap in the outcomes measured or the analytical methods employed. There was concordance in three studies reporting no microbial growth over 4-9 days of refrigerated storage, and in five studies reporting a reduction in fat during 1-8 months of frozen storage. Only one study assessed the storage of HPDHM that had been fortified.

CONCLUSIONS

Long-term refrigerated and frozen storage of HPDHM affects some components in milk more than others. While there is evidence of microbial purity during four or more days of refrigerated storage in clinical conditions, there is limited research on the impact of macro and micronutrients, or the impact of fortifiers. More research is needed in these areas.