Neurodevelopmental outcomes of extremely preterm infants fed an exclusive human milk-based diet versus a mixed human milk + bovine milk-based diet: a multi-center study.

OBJECTIVE: The objective of this multi-center study was to compare, in infants ≤1250 g birth weight (BW) with neurodevelopmental assessment at 18-22 months of corrected age (CA), whether their neurodevelopmental outcomes differed based on exposure to an exclusive human milk-based (HUM) or to a bovine milk-based fortifier and/or preterm formula (BOV). STUDY DESIGN: Retrospective multi-center cohort study of infants undergoing neurodevelopmental assessment as to whether HUM or BOV exposure related to differences in outcomes of infants at 18-22 months CA, using the Bayley Scales of Infant Development III (BSID-III). BSID-III cognitive, language, and motor scores were adjusted for BW, sex, study site, and necrotizing enterocolitis. RESULTS: 252 infants from 6 centers were included. BSID-III cognitive scores were higher in the HUM group (96.5 ± 15.1 vs 89.6 ± 14.1, adjusted p = 0.0001). Mean BSID-III language scores were 85.5 ± 15.0 in HUM and 82.2 ± 14.1 in BOV (adjusted p = 0.09). Mean BSID-III motor scores were 92.9 ± 11.7 in HUM and 91.4 ± 14.6 in BOV (adjusted p = 0.32). CONCLUSION: In this cohort of infants undergoing neurodevelopmental assessment, infants receiving HUM diet had significantly higher cognitive BSID-III scores at 18-22 months CA. Further investigation is needed of this potential for HUM to positively influence infant cognitive outcomes.

Is the Antioxidant Capacity of Stored Human Milk Preserved?

Background: In the neonatal intensive care unit (NICU) expressed mothers' milk usually is stored frozen until used. We found that when human milk was stored at -20°C for up to 9 months there were reduced bacterial counts and pH, increased free fatty acids, but unchanged immune proteins. Antioxidant protection is an important benefit of human milk. Few studies have evaluated long-term effects of cold storage on the antioxidant capacity of human milk. We hypothesized that the antioxidant capacity of human milk is affected adversely by long-term storage at -20°C. Objective: To study the impact of long-term cold storage on the oxidative capacity of human milk and the biological impact of these changes on macromolecular constituents of human milk. Methods: Freshly expressed milk was obtained from mothers in the NICU, stored at -20°C for 6 months, and compared with the baseline. Paired samples were analyzed for glutathione, hydrogen peroxide (H2O2), 8-isoprostane, catalase, and superoxide dismutase. Results: There was no change in H2O2 concentration between baseline and 6 months. Significant reductions from baseline in both catalase and superoxide dismutase concentrations and activities, total glutathione, oxidized glutathione, reduced glutathione, and the ratio of reduced to oxidized glutathione were observed (p < 0.05). There was a significant increase in 8-isoprostane concentrations (p < 0.001). Conclusion: These data indicate significant changes in antioxidant capacity of human milk, including oxidation of macromolecules, after storage at -20°C for 6 months. The clinical implication of these findings may explain the nonuniform protection against oxidant disease in preterm infants fed human milk.

Bacterial stability with freezer storage of human milk.

OBJECTIVES: Human milk supports the development of a beneficial newborn intestinal microflora. We have shown previously that human milk had reduced bacteria but unchanged nutrient composition when stored at -20 °C for up to nine months. We suspected declining bacterial colony counts were manifestations of bacterial dormancy and not failure of survival. We investigated differences in selected bacterial colony counts (lactobacillus, bifidobacteria, staphylococcus, streptococcus and enterococcus) in human milk stored for 2 and 12 weeks at -20 °C in either manual or automatic defrost freezers and whether reduced bacterial counts at 12 weeks were the result of dormancy or failure of survival. METHODS: Freshly expressed milk was obtained from mothers in the NICU, divided into aliquots and stored for 2 and 12 weeks at -20 °C in either automatic or manual defrost freezers. Subsequently, duplicate aliquots, one thawed and the other thawed and maintained at room temperature for 4 h, were plated to assess bacterial colony counts. RESULTS: Significant declines in bacterial colony counts were seen from 2 to 12 weeks freezer storage for all bacteria. There were no differences in colony counts between freezer types. Once thawed, no further bacterial growth occurred. CONCLUSIONS: Short-term freezer storage for 12 weeks resulted bacterial killing. Type of freezer used for storage did not have an impact on bacterial survival. It is unknown whether the paucity of important probiotic bacteria in stored human milk has adverse effects on infants.

Relationship Between Milk Fat Globule-Epidermal Growth Factor 8 and Intestinal Cytokines in Infants Born Preterm.

OBJECTIVES: To investigate the relationships between dietary intake and fecal concentrations of milk fat globule-epidermal growth factor 8 (MFG-E8), and between fecal concentrations of MFG-E8 and markers of intestinal inflammation in infants born preterm. STUDY DESIGN: Fecal samples were collected daily and enteral feedings were sampled weekly. MFG-E8 in enteral feedings and feces, and cytokine concentrations in feces were quantified by enzyme-linked immunosorbent assay. RESULTS: Milk MFG-E8 concentrations were significantly greater in unfortified mother's own milk (MOM) and MOM with human milk fortifier than either donor human milk or preterm formula. MFG-E8 concentrations in fecal samples were positively correlated with MFG-E8 concentrations in respective milks. High MFG-E8 exposure (≥60 mL/kg/day of feedings that include MOM or MOM with human milk fortifier) was associated with lower concentrations of proinflammatory cytokines (interleukin-8, tumor necrosis factor-α, and monocyte chemoattractant protein-1) and higher concentrations of the anti-inflammatory cytokine interleukin-4 in feces, compared with low MFG-E8 exposure. CONCLUSIONS: Infants born preterm who were fed MOM had greater concentrations of MFG-E8 and lower concentrations of proinflammatory cytokines in fecal samples than other diets or no feedings. These data further support the protective role of MOM, possibly because of MFG-E8, against intestinal inflammation.

Does Human Milk Fortifier Affect Intestinal Inflammation in Preterm Infants?

Background: Fecal calprotectin, a recognized marker of intestinal inflammation, is derived from neutrophil migration to a site of inflammation. Introduction of bovine-based human milk fortifier containing intact protein in preterm infants is associated with an increase in fecal calprotectin suggestive of intestinal inflammation. Newer fortifiers contain protein hydrolysates in place of intact protein. Objective: To measure fecal calprotectin in human milk-fed preterm infants before and after human milk fortification using a fortifier containing hydrolyzed protein. Methods: Serial stool samples were collected from 24 infants beginning at the first week to 60 days postnatal age. To compare the effect of human milk fortification, samples collected before and after fortification were compared. Infant demographics, diet, postnatal morbidities, and maternal characteristics were recorded. Results: A total of 401 stool samples were collected from 24 study infants who had a birth weight of 993 ± 277 g (mean ± standard deviation), gestational age 27.5 ± 2.8 weeks, and fortifier initiation at 14 days. Median fecal calprotectin before and after fortification were similar. Calprotectin levels were not correlated with birth weight or gestational age but were inversely correlated with postnatal age (p = 0.005), use of fortifier (p < 0.001), receipt of antibiotics antenatally (p = 0.007) and postnatally (p = 0.008). After adjusting for postnatal age, calprotectin levels were significantly lower following receipt of fortifier (p < 0.001) and postnatal antibiotics (p < 0.001). Conclusions: The feeding of protein hydrolysate-containing human milk fortifiers does not appear to be associated with increases in a marker of intestinal inflammation.

"Extrauterine growth restriction" and "postnatal growth failure" are misnomers for preterm infants.

Preterm infants are increasingly diagnosed as having "extrauterine growth restriction" (EUGR) or "postnatal growth failure" (PGF). Usually EUGR/PGF is diagnosed when weight is <10th percentile at either discharge or 36-40 weeks postmenstrual age. The reasons why the phrases EUGR/PGF are unhelpful include, they: (i) are not predictive of adverse outcome; (ii) are based only on weight without any consideration of head or length growth, proportionality, body composition, or genetic potential; (iii) ignore normal postnatal weight loss; (iv) are usually assessed prior to growth slowing of the reference fetus, around 36-40 weeks, and (v) are usually based on an arbitrary statistical growth percentile cut-off. Focus on EUGR/PGF prevalence may benefit with better attention to nutrition but may also harm with nutrition delivery above infants' actual needs. In this paper, we highlight challenges associated with such arbitrary cut-offs and opportunities for further refinement of understanding growth and nutritional needs of preterm neonates.

Metabolic Acidosis in Preterm Infants is Associated with a Longer Length of Stay in the Neonatal Intensive Care Unit.

INTRODUCTION: Preterm births account for disproportionately high healthcare costs, in large part due to expenses related to length of stay in the hospital neonatal intensive care unit (NICU). It is common for preterm infants to receive human milk fortifier (HMF) while in the NICU. Liquid HMF is available in both acidified and non-acidified formulations. A recent randomized clinical trial found that acidified HMF is associated with an increased incidence of metabolic acidosis, which may contribute to increased costs and longer NICU length of stay. OBJECTIVE: The present study is a secondary analysis of these data, seeking to determine whether additional factors contribute to metabolic acidosis, whether metabolic acidosis is associated with longer hospital length of stay, and whether these associations contribute to the burden of hospital costs. METHODS: The study sample consisted of 152 infants who were hospitalized in US NICUs. Multiple logistic regression was used to model the NICU length of stay. Data from the 2012 Healthcare Cost and Utilization Project (HCUP) Kids' Inpatient Database (KID) were used to calculate the average cost (charge) per day in a NICU. Costs (charges) were adjusted to $US, year 2018 values, using the health Consumer Price Index. RESULT: Results indicated that acidified HMF was a strong predictor of metabolic acidosis, more so than gestational age or birth weight. Furthermore, metabolic acidosis was associated with incremental NICU costs (charges) of $US19,002 ($US65,462) per infant and longer NICU LOS. CONCLUSION: Future studies should further investigate factors that contribute to NICU length of stay and associated costs of care. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02307760.

Early oral colostrum administration in preterm infants.

BACKGROUND: Early administration of colostrum may provide preterm infants with immune components. Previous studies illustrating the effects of oral colostrum (OC) have been confounded by the coincidence of enteral feedings. OBJECTIVE: To quantify OC absorption, as measured by urinary sIgA and lactoferrin, in preterm infants prior to enteral feedings. MATERIALS AND METHODS: Colostrum was obtained from mothers delivering infants ≤32 weeks and ≤1500 g. sIgA and lactoferrin were measured in infant urine, and microflora in saliva and tracheal aspirates were characterized. RESULTS: Urinary sIgA and lactoferrin were significantly greater in infants receiving OC by syringe compared to swab (p < 0.002). Urinary sIgA correlated with the total number of doses in 72 h (R2 = 43%, p < 0.01). CONCLUSIONS: Administration of OC by syringe and higher cumulative dose are associated with increased absorption of sIgA and lactoferrin, and early dosing may contribute to a more diverse tracheal microbiome.

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.

Pasteurization Preserves IL-8 in Human Milk.

Background: Pasteurized donor human milk is an alternative feeding when mothers' own milk is not available for premature infants. The effects of pasteurization on the host defense properties of human milk are unclear. We investigated the effects of Holder pasteurization on concentrations of anti-inflammatory and pro-inflammatory cytokines in human milk. Objective: To compare concentrations of anti-inflammatory and pro-inflammatory cytokines before and after pasteurization of donor human milk. Study Design: A single milk sample was obtained from each of 24 mothers of premature infants in the neonatal intensive care unit by electric breast pump and was stored at -80°C. At the time of pasteurization, milk samples were thawed and divided into two aliquots. The first aliquot was re-stored at -80°C and the second aliquot was heat-treated at 62.5°C for 30 min and then re-stored at -80°C. At the time of batch cytokine analyses samples were thawed rapidly. Results: Most cytokine concentrations declined following pasteurization. The most prevalent cytokine, IL-8, was preserved (89%) following pasteurization. There were no relationships between gestational age, postnatal age of milk collection, duration of milk storage, and the concentrations cytokines. Conclusion: In contrast to most cytokines after pasteurization, IL-8 is preserved or liberated from another compartment. The maintenance of IL-8 in human milk after pasteurization and the loss of anti-inflammatory cytokines following pasteurization, suggests that the effects of inflammatory activity in pasteurized human milk should be evaluated. These data may account, in part, for the lesser protective effect on the host of pasteurized donor human milk compared with mother's own milk.

Improved Outcomes in Preterm Infants Fed a Nonacidified Liquid Human Milk Fortifier: A Prospective Randomized Clinical Trial.

OBJECTIVE: To compare growth, feeding tolerance, and clinical and biochemical evaluations in human milk-fed preterm infants randomized to receive either an acidified or a nonacidified liquid human milk fortifier. STUDY DESIGN: This prospective, controlled, parallel, multicenter growth and tolerance study included 164 preterm infants (≤32 weeks of gestation, birth weight 700-1500 g) who were randomized to acidified or nonacidified liquid human milk fortifier from study day 1, the first day of fortification, through study day 29 or until hospital discharge. RESULTS: There was no difference in the primary outcome of weight gain from study days 1 to 29 (acidified liquid human milk fortifier, 16.4 ± 0.4 g/kg/day; nonacidified liquid human milk fortifier, 16.9 ± 0.4 g/kg/day). However, in both the intention-to-treat and the protocol evaluable analyses, infants fed nonacidified liquid human milk fortifier had significantly greater weight gain from study days 1 to 15 (17.9 g/kg/day vs 15.2 g/kg/day; P = .001). Infants fed with acidified liquid human milk fortifier received more protein (4.26 vs g/kg/day 4.11 g/kg/day, P = .0099) yet had lower blood urea nitrogen values (P = .010). The group fed acidified liquid human milk fortifier had more vomiting (10.3% vs 2.4%; P = .018), gastric residuals (12.8% vs 3.7%; P = .022), and metabolic acidosis (27% vs 5%; P < .001) in the intention-to-treat analysis and more abdominal distension (14.0% vs 1.7%; P = .015) in the protocol evaluable analysis. CONCLUSIONS: Infants fed an acidified liquid human milk fortifier had higher rates of metabolic acidosis and poor feeding tolerance compared with infants fed a nonacidified liquid human milk fortifier. Initial weight gain was poorer with the acidified liquid human milk fortifier. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02307760.

National Trends in Pediatricians' Practices and Attitudes About Breastfeeding: 1995 to 2014.

BACKGROUND AND OBJECTIVES: The American Academy of Pediatrics (AAP) has affirmed breastfeeding as the preferred method of infant feeding; however, there has been little systematic examination of how pediatricians' recommendations, affiliated hospitals' policies, counseling practices, and attitudes toward breastfeeding have shifted over the past 2 decades. These trends were examined from 1995 to 2014. METHODS: Data are from the Periodic Survey (PS) of Fellows, a nationally representative survey of AAP members. PS #30 (1995; response rate = 72%; N = 832), PS #57 (2004; response rate = 55%; N = 675), and PS #89 (2014; response rate = 51%; N = 620) collected demographics, patient and practice characteristics, and detailed responses on pediatricians' recommendations, affiliated hospitals' policies, counseling practices, and attitudes toward breastfeeding. By using bivariate statistics and logistic regression models, the analysis investigated changes over time with predicted values (PVs). RESULTS: From 1995 to 2014, more pediatricians reported their affiliated hospitals applied for "baby-friendly" designation (PV = 12% in 1995, PV = 56% in 2014; P < .05), and more reported that they recommend exclusive breastfeeding (65% to 76% [P < .05]). However, fewer respondents indicated that mothers can be successful breastfeeding (PV = 70% in 1995, PV = 57% in 2014; P < .05) and that the benefits outweigh the difficulties (PV = 70% in 1995, PV = 50% in 2014; P < .05). Younger pediatricians were less confident than older pediatricians in managing breastfeeding problems (P < .01). CONCLUSIONS: Pediatricians' recommendations and practices became more closely aligned with AAP policy from 1995 to 2014; however, their attitudes about the likelihood of breastfeeding success have worsened. These 2 divergent trends indicate that even as breastfeeding rates continue to rise, continued efforts to enhance pediatricians' training and attitudes about breastfeeding are necessary.

Human milk is the feeding strategy to prevent necrotizing enterocolitis!

Human milk is the preferred diet for preterm infants as it protects against a multitude of NICU challenges, specifically necrotizing enterocolitis. Infants who receive greater than 50% of mother's own milk (MOM) in the 2 weeks after birth have a significantly decreased risk of NEC. An additional factor in the recent declining rates of NEC is the increased utilization of donor human milk (DHM). This creates a bridge until MOM is readily available, thus decreasing the exposure to cow milk protein. Preterm infants are susceptible to NEC due to the immaturity of their gastrointestinal and immune systems. An exclusive human milk diet compensates for these immature systems in many ways such as lowering gastric pH, enhancing intestinal motility, decreasing epithelial permeability, and altering the composition of bacterial flora. Ideally, preterm infants should be fed human milk and avoid bovine protein. A diet consisting of human milk-based human milk fortifier is one way to provide the additional nutritional supplements necessary for adequate growth while receiving the protective benefits of a human milk diet.

Oxytocin, a main breastfeeding hormone, prevents hypertension acquired in utero: A therapeutics preview.

Hypertension is a major risk factor for ischemic heart disease and stroke, leading causes of morbidity and death worldwide. Intrauterine growth restriction (IUGR), caused by an excess of glucocorticoid exposure to the fetus, produces an imbalance in oxidative stress altering many biochemical and epigenetic gene transcription processes exposing the fetus and neonate to the 'thrifty' phenotype and pervasive polymorphisms appearance damaging health, cognitive, and behavioral processes in later life. OT is a major regulator of oxidative stress radicals that plays a major role in neonatal maturation of the central nervous system and many peripheral tissues expressing oxytocin/oxytocin-receptor (OT/OTR) system in the early postnatal period. OT and OTR are damaged by IUGR and early stress. This review highlights the fact that hypertension is likely to be a legacy of preterm birth due to IUGR and failure to meet nutritional needs in early infancy when fed formula instead of breastfeeding or human milk.

Effects of Extended Freezer Storage on the Integrity of Human Milk.

OBJECTIVE: To examine the integrity (pH, bacterial counts, host defense factors, nutrient contents, and osmolality) of freshly expressed and previously refrigerated human milk subjected to long-term freezer storage. STUDY DESIGN: Mothers donated 100 mL of freshly expressed milk. Samples were divided into baseline, storage at -20°C (fresh frozen) for 1, 3, 6, and 9 months, and prior storage at +4°C for 72 hours (refrigerated frozen) before storage at -20°C for 1 to 9 months. Samples were analyzed for pH, total bacterial colony count, gram-positive and gram-negative colony counts, and concentrations of total protein, fat, nonesterified fatty acids, lactoferrin, secretory IgA, and osmolality. RESULTS: Milk pH, total bacterial colony count, and Gram-positive colony counts decreased significantly with freezer storage (P < .001); bacterial counts decreased most rapidly in the refrigerated frozen group. The gram-negative colony count decreased significantly over time (P < .001). Nonesterified fatty acid concentrations increased significantly with time in storage (P < .001). Freezing for up to 9 months did not affect total protein, fat, lactoferrin, secretory IgA, or osmolality in either group. CONCLUSIONS: Freezer storage of human milk for 9 months at -20°C is associated with decreasing pH and bacterial counts, but preservation of key macronutrients and immunoactive components, with or without prior refrigeration for 72 hours. These data support current guidelines for freezer storage of human milk for up to 9 months for both freshly expressed and refrigerated milk.