Comparison of the effect of two human milk fortifiers on clinical outcomes in premature infants

Difference in the Intestinal Microbiota between Breastfeed Infants and Infants Fed with Artificial Milk: A Systematic Review

The gut microbiota (GM) plays a crucial role in human health, particularly during the first years of life. Differences in GM between breastfed and formula (F)-fed infants may influence long-term health outcomes. This systematic review aims to compare the gut microbiota of breastfed infants with that of F-fed infants and to evaluate the clinical implications of these differences. We searched databases on Scopus, Web of Science, and Pubmed with the following keywords: "gut microbiota", "gut microbiome", and "neonatal milk". The inclusion criteria were articles relating to the analysis of the intestinal microbiome of newborns in relation to the type of nutrition, clinical studies or case series, excluding reviews, meta-analyses, animal models, and in vitro studies. The screening phase ended with the selection of 13 publications for this work. Breastfed infants showed higher levels of beneficial bacteria such as Bifidobacterium and Lactobacillus, while F-fed infants had a higher prevalence of potentially pathogenic bacteria, including Clostridium difficile and Enterobacteriaceae. Infant feeding type influences the composition of oral GM significantly. Breastfeeding promotes a healthier and more diverse microbial ecosystem, which may offer protective health benefits. Future research should explore strategies to improve the GM of F-fed infants and understand the long-term health implications.

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.

Acidified Feedings in Preterm Infants: A Historical and Physiological Perspective

The use of acidified milk for feeding infants has a long, interesting history that appears to have developed from the use of buttermilk in Holland as early as the late 19th century for feeding infants with diarrhea. Physicians in the early 20th century assumed that the observed benefits were from buttermilk's acidity leading to the practice of acidifying infant formula. The historical and physiological perspective on the use of acidified infant formula is now especially relevant with the emergence of an acidified liquid human milk fortifier for preterm infants. Here, we review that history, with a deeper dive into the contemporary research on the use of acidified human milk fortifiers, the consequences for preterm infants, and the underlying physiological mechanisms. KEY POINTS: · In the late 19th and early 20th century acidified feedings were in common use for sick infants.. · By the mid-20th century, acidified feedings tested in preterm infants resulted in acidic physiology and poor growth.. · The current practice of acidifying feedings in preterm infants has been associated with metabolic acidosis, poor tolerance, and delayed growth..

An Adaptation of the Skin Safety Model to Guide Diaper Dermatitis Research in the NICU

Diaper dermatitis is an ever-present condition among infants. Little is known about the prevalence among infants in the NICU. This article presents an adaptation of the skin safety model (SSM) for the infant in the NICU. The concepts of the model were extracted, defined, and integrated into an adapted SSM model to provide a focus on the infant with diaper dermatitis in the intensive care setting. It is essential to include all factors of the infant's clinical characteristics and hospital experience in the modeling to accurately predict risk of skin vulnerability in this infant population.

Novel multinutrient human milk-based human milk fortifier promotes growth and tolerance in premature infants

BACKGROUND

The objective of this study was to determine whether human milk supplemented with a novel human milk-based human milk fortifier (Novel HMF), compared with a bovine milk-based HMF (Bovine HMF), supports preterm infant growth through 36 weeks' postmenstrual age (PMA).

METHODS

This single-center, prospective trial compared growth and nutrition outcomes of preterm infants provided a human milk-based diet (mother's own milk or donor milk) supplemented with a Novel HMF with historic controls provided Bovine HMF. Preterm infants with an estimated gestational age (EGA) between 23 and 33 weeks' PMA and birth weight between 750 and 1800 g were eligible for study inclusion. Weight, length, and head circumference (HC) were monitored weekly. The occurrence of late-onset sepsis, nil per os (NPO) days, necrotizing enterocolitis, metabolic acidosis, and serious adverse events were monitored.

RESULTS

Birth weight, length, HC, and EGA were similar between the Novel HMF (n = 37) and Bovine HMF (n = 49) groups. The days to regain birth weight was shorter in the Novel HMF group (9.4 ± 4.0 vs 11.4 ± 4.8, P = .0343), with similar weight gain (g/day) from birth to 36 weeks' PMA. Adjusted weight growth velocity (g/kg/day) was significantly higher in the Novel HMF group at 14 and 21 days but similar at 36 weeks' PMA. The Novel HMF group experienced fewer NPO days with a similar total number of feeding days.

CONCLUSIONS

A novel, multinutrient, human milk-based HMF is well tolerated and meets the nutrition needs of preterm infants.

Fortification of Breast Milk With Preterm Formula Powder vs Human Milk Fortifier in Preterm Neonates: A Randomized Noninferiority Trial

IMPORTANCE

Fortification of expressed breast milk (EBM) using commercially available human milk fortifiers (HMF) increases short-term weight and length in preterm very low-birth-weight (VLBW) neonates. However, the high cost and increased risk of feed intolerance limit their widespread use. Preterm formula powder fortification (PTF) might be a better alternative in resource-limited settings.

OBJECTIVE

To demonstrate that fortification of EBM by preterm formula powder is noninferior to fortification by HMF, in terms of short-term weight gain, in VLBW neonates.

DESIGN, SETTING, AND PARTICIPANTS

Open-label, noninferiority, randomized trial conducted from December 2017 to June 2019 at a level 3 neonatal unit in India. The trial enrolled preterm (born at or before 34 weeks of gestation) VLBW neonates receiving at least 100 mL/kg/d of feeds and consuming 75% of milk or more as EBM.

INTERVENTIONS

Neonates were randomly assigned to receive fortification by either PTF or HMF. Calcium, phosphorus, iron, vitamin D, and multivitamins were supplemented in PTF and only vitamin D in the HMF group to meet the recommended dietary allowances.

MAIN OUTCOMES AND MEASURES

The primary outcome was the weight gain until discharge from the hospital or 40 weeks' postmenstrual age, whichever was earlier; the prespecified noninferiority margin was 2 g/kg/d. Secondary outcomes included morbidities such as necrotizing enterocolitis, feed intolerance, and extrauterine growth restriction (<10th percentile on the Fenton chart at 40 weeks' postmenstrual age).

RESULTS

Of the 123 neonates enrolled, 60 and 63 were randomized to the PTF and HMF groups, respectively. The mean gestation (30.5 vs 29.9 weeks) and birth weight (1161 vs 1119 g) were comparable between the groups. There was no difference in the mean (SD) weight gain between the PTF and HMF groups (15.7 [3.9] vs 16.3 [4.0] g/kg/d; mean difference, -0.5 g/kg/d; 95% CI, -1.9 to 0.7). The lower bound of 95% CI did not cross the noninferiority margin. The incidence of feed intolerance was lower in the PTF group (1.4 vs 6.8 per 1000 patient-days; incidence rate ratio 0.19; 95% CI, 0.04 to 0.95), and fewer neonates required withholding of fortification for 24 hours or more (5% vs 22%; risk ratio, 0.22; 95% CI, 0.07 to 0.75). The incidence of necrotizing enterocolitis stage II or more (0 vs 5%) and extrauterine growth restriction (73% vs 81%) was comparable between the groups.

CONCLUSIONS AND RELEVANCE

Fortification with preterm formula powder is not inferior to fortification with human milk fortifiers in preterm neonates. Given the possible reduction in feed intolerance and lower costs, preterm formula might be a better option for fortification, especially in resource-restricted settings.

TRIAL REGISTRATION

Clinical Trial Registry, India Identifier: CTRI/2017/11/010593.

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.

Comparison of different protein concentrations of human milk fortifier for promoting growth and neurological development in preterm infants

BACKGROUND

Human milk alone may provide inadequate amounts of protein to meet the growth requirements of preterm infants because of restrictions in the amount of fluid they can tolerate. It has become common practice to feed preterm infants with breast milk fortified with protein and other nutrients but there is debate about the optimal concentration of protein in commercially available fortifiers.

OBJECTIVES

To compare the effects of different protein concentrations in human milk fortifier, fed to preterm infants, on growth and neurodevelopment.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search CENTRAL (2019, Issue 8), Ovid MEDLINE and CINAHL on 15 August 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included all published and unpublished randomised, quasi-randomised and cluster-randomised trials comparing two different concentrations of protein in human milk fortifier. We included preterm infants (less than 37 weeks' gestational age). Participants may have been exclusively fed human milk or have been supplemented with formula. The concentration of protein was classified as low (< 1g protein/100 mL expressed breast milk (EBM)), moderate (≥ 1g to < 1.4g protein/100 mL EBM) or high (≥ 1.4g protein/100 mL EBM). We excluded trials that compared two protein concentrations that fell within the same category.

DATA COLLECTION AND ANALYSIS

We undertook data collection and analyses using the standard methods of Cochrane Neonatal. Two review authors independently evaluated trials. Primary outcomes included growth, neurodevelopmental outcome and mortality. Data were synthesised using risk ratios (RR), risk differences and mean differences (MD), with 95% confidence intervals (CI). We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We identified nine trials involving 861 infants. There is one trial awaiting classification, and nine ongoing trials. The trials were mostly conducted in infants born < 32 weeks' gestational age or < 1500 g birthweight, or both. All used a fortifier derived from bovine milk. Two trials fed infants exclusively with mother's own milk, three trials gave supplementary feeds with donor human milk and four trials supplemented with preterm infant formula. Overall, trials were small but generally at low or unclear risk of bias. High versus moderate protein concentration of human milk fortifier There was moderate certainty evidence that a high protein concentration likely increased in-hospital weight gain compared to moderate concentration of human milk fortifier (MD 0.66 g/kg/day, 95% CI 0.51 to 0.82; trials = 6, participants = 606). The evidence was very uncertain about the effect of high versus moderate protein concentration on length gain (MD 0.01 cm/week, 95% CI -0.01 to 0.03; trials = 5, participants = 547; very low certainty evidence) and head circumference gain (MD 0.00 cm/week, 95% CI -0.01 to 0.02; trials = 5, participants = 549; very low certainty evidence). Only one trial reported neonatal mortality, with no deaths in either group (participants = 45). Moderate versus low protein concentration of human milk fortifier A moderate versus low protein concentration fortifier may increase weight gain (MD 2.08 g/kg/day, 95% CI 0.38 to 3.77; trials = 2, participants = 176; very low certainty evidence) with little to no effect on head circumference gain (MD 0.13 cm/week, 95% CI 0.00 to 0.26; I² = 85%; trials = 3, participants = 217; very low certainty evidence), but the evidence is very uncertain. There was low certainty evidence that a moderate protein concentration may increase length gain (MD 0.09 cm/week, 95% CI 0.05 to 0.14; trials = 3, participants = 217). Only one trial reported mortality and found no difference between groups (RR 0.48, 95% CI 0.05 to 5.17; participants = 112). No trials reported long term growth or neurodevelopmental outcomes including cerebral palsy and developmental delay.

AUTHORS' CONCLUSIONS

Feeding preterm infants with a human milk fortifier containing high amounts of protein (≥ 1.4g/100 mL EBM) compared with a fortifier containing moderate protein concentration (≥ 1 g to < 1.4 g/100 mL EBM) results in small increases in weight gain during the neonatal admission. There may also be small increases in weight and length gain when infants are fed a fortifier containing moderate versus low protein concentration (< 1 g protein/100 mL EBM). The certainty of this evidence is very low to moderate; therefore, results may change when the findings of ongoing studies are available. There is insufficient evidence to assess the impact of protein concentration on adverse effects or long term outcomes such as neurodevelopment. Further trials are needed to determine whether modest increases in weight gain observed with higher protein concentration fortifiers are associated with benefits or harms to long term growth and neurodevelopment.

Protein supplementation of human milk for promoting growth in preterm infants

BACKGROUND

Preterm infants require high protein intake to achieve adequate growth and development. Although breast milk feeding has many benefits for this population, the protein content is highly variable, and inadequate to support rapid infant growth. This is a 2020 update of a Cochrane Review first published in 1999.

OBJECTIVES

To determine whether protein-supplemented human milk compared with unsupplemented human milk, fed to preterm infants, improves growth, body composition, cardio-metabolic, and neurodevelopmental outcomes, without significant adverse effects.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 8) in the Cochrane Library and MEDLINE via PubMed on 23 August 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Published and unpublished RCTs were eligible if they used random or quasi-random methods to allocate hospitalised preterm infants who were being fed human milk, to additional protein supplementation or no supplementation.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data, assessed risk of bias and the quality of evidence at the outcome level, using GRADE methodology. We performed meta-analyses, using risk ratio (RR) for dichotomous data, and mean difference (MD) for continuous data, with their respective 95% confidence intervals (CIs). We used a fixed-effect model and had planned to explore potential causes of heterogeneity via subgroup or sensitivity analyses.

MAIN RESULTS

We included six RCTs, involving 204 preterm infants. The risk of bias for most methodological domains was unclear as there was insufficient detail reported. Low-quality evidence showed that protein supplementation of human milk may increase in-hospital rates of growth in weight (MD 3.82 g/kg/day, 95% CI 2.94 to 4.7; five RCTs, 101 infants; I² = 73%), length (MD 0.12 cm/wk, 95% CI 0.07 to 0.17; four RCTs, 68 infants; I² = 89%), and head circumference (MD 0.06 cm/wk, 95% CI 0.01 to 0.12; four RCTs, 68 infants; I² = 84%). Protein supplementation may lead to longer hospital stays (MD 18.5 days, 95% CI 4.39 to 32.61; one RCT, 20 infants; very low-quality evidence). Very low quality evidence means that the effect of protein supplementation on the risk of feeding intolerance (RR 2.70, 95% CI 0.13 to 58.24; one RCT, 17 infants), or necrotizing enterocolitis (RR 1.11, 95% CI 0.07 to 17.12; one RCT, 76 infants) remains uncertain. No data were available about the effects of protein supplementation on neurodevelopmental outcomes.

AUTHORS' CONCLUSIONS

Low-quality evidence showed that protein supplementation of human milk, fed to preterm infants, increased short-term growth. However, the small sample sizes, low precision, and very low-quality evidence regarding duration of hospital stay, feeding intolerance, and necrotising enterocolitis precluded any conclusions about these outcomes. There were no data on outcomes after hospital discharge. Our findings may not be generalisable to low-resource settings, as none of the included studies were conducted in these settings. Since protein supplementation of human milk is now usually done as a component of multi-nutrient fortifiers, future studies should compare different amounts of protein in multi-component fortifiers, and be designed to determine the effects on duration of hospital stay and safety, as well as on long-term growth, body composition, cardio-metabolic, and neurodevelopmental outcomes.

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.

Feeding practice influences gut microbiome composition in very low birth weight preterm infants and the association with oxidative stress: A prospective cohort study

Knowledge about the development of the preterm infant gut microbiota is emerging and is critical to their health. Very-low-birth-weight (VLBW; birth weight, <1500 g) infants usually have special dietary needs while showing increased oxidative stress related to intensive care. This prospective cohort study assessed the effect of feeding practice on gut microbiome development and oxidative stress in preterm infants. Fecal samples were collected from each infant in the early (1-2 weeks of enteral feeding) and late (2-4 weeks of enteral feeding) feeding stages. We performed high-throughput sequencing of V3-V4 regions of the 16S rRNA gene to analyze the fecal microbiome composition of 20 VLBW preterm infants and to determine the association of gut bacterial composition with feeding practice using an oxidative stress marker (urinary F2-isoprostane). Our results showed that feeding practices in the late stage significantly influenced the gut microbiome composition and oxidative stress in preterm infants. Preterm infants fed human milk + human milk fortifier and only formula diets showed a significant increase in F2-isoprostane levels (P < 0.05) compared with those fed human milk + formula diet. The gut microbiome of the infants fed the human milk + Human milk fortifier diet showed the lower relative abundance of Veillonella (P < 0.05) compared with that of the infants fed the human milk + formula diet. The gut microbiome of the infants fed the only formula diet showed the lowest microbial diversity and the highest relative abundance of Terrisporobacter (P < 0.05) compared with the gut microbiome of the infants fed the other diets. Correlation network analysis showed that urinary F2-isoprostane level was positively correlated with Terrisporobacter and Enterobacteriaceae abundance (P < 0.05) in the preterm infants. In conclusion, these data suggest that feeding practice affects the bacterial diversity and composition in the gut microbiome and is associated with oxidative stress in VLBW preterm infants.

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.

Tolerance of Hydrolyzed Liquid Protein Fortified Human Milk and Effect on Growth in Premature Infants

BACKGROUND

We evaluated tolerance of hydrolyzed liquid protein (LP) supplement added to fortified human milk (HM) to optimize protein intake in preterm infants.

METHODS

A prospective observational study of 31 subjects compared with 31 historic controls, receiving mothers own milk (MOM) and/or donor milk (DM) to assess LP tolerance, growth, and risk for morbidities was conducted. Milk was analyzed for nutrient content. Feeding intolerance, defined as cessation of feedings for ≥48 hours, abdominal distension and/or residuals, necrotizing enterocolitis (NEC), and metabolic acidosis were used to assess safety, while weight and head circumference (HC) were used to evaluate growth.

RESULTS

LP added to powder-fortified HM had no impact on feeding intolerance and NEC. Biochemical parameters showed no metabolic acidosis: blood urea nitrogen levels (first week: median, 13 mg/dL; interquartile range [IQR], 9-16; last week: median, 13 mg/dL; IQR, 10.3-14; P = .94), bicarbonate levels (first week: median, 26.3 mEq/L; IQR, 24-28; last week: median, 28 mEq/L; IQR, 26.3-29.8; P = .10), and pH levels (first week: median, 7.4; IQR, 7.3-7.4; last week: median, 7.4; IQR, 7.37-7.40; P = .5). Weight and HC were not statistically significant. HM analysis showed lower protein and caloric content, respectively (MOM: 0.88 vs DM: 0.77 g/100 mL; P < .0001 and MOM: 18.68 vs DM: 17.96 kcal/oz; P = .02).

CONCLUSIONS

Hydrolyzed LP is well tolerated in preterm infants with no difference in growth rates. Clinicians should focus on the need to maximize both protein and energy to optimize growth.

Evaluation of A Concentrated Preterm Formula as a Liquid Human Milk Fortifier in Preterm Babies at Increased Risk of Feed Intolerance

There are concerns around safety and tolerance of powder human milk fortifiers to optimize nutrition in preterm infants. The purpose of this study was to evaluate the tolerance and safety of a concentrated preterm formula (CPF) as a liquid human milk fortifier (HMF) for premature infants at increased risk of feeding intolerance. We prospectively enrolled preterm infants over an 18-month period, for whom a clinical decision had been made to add CPF to human milk due to concerns regarding tolerance of powder HMF. Data on feed tolerance, anthropometry, and serum biochemistry values were recorded. Serious adverse events, such as mortality, necrotizing enterocolitis (NEC), and sepsis, were monitored. A total of 29 babies received CPF fortified milk during the study period. The most common indication for starting CPF was previous intolerance to powder HMF. Feeding intolerance was noted in 4 infants on CPF. The growth velocity of infants was satisfactory (15.9 g/kg/day) after addition of CPF to feeds. The use of CPF as a fortifier in preterm babies considered at increased risk for feed intolerance seems well tolerated and facilitates adequate growth. Under close nutrition monitoring, this provides an additional option for human milk fortification in this challenging subgroup of preterm babies, especially in settings with limited human milk fortifier options.

Commencing Nutrient Supplements before Full Enteral Feed Volume Achievement Is Beneficial for Moderately Preterm to Late Preterm Low Birth Weight Babies: A Prospective, Observational Study

The aim of this study was to observe after following a routine change in the feeding protocol whether the earlier introduction of nutrient supplements improved nutritional outcomes in moderately preterm to late preterm low birth weight (LBW) babies. In this prospective observational study, LBW babies between 31 and 39 weeks’ gestation admitted to a Special Care Nursery were assigned to two groups (F80, n = 45, F160, n = 42) upon commencing nutrient supplement at total fluid intake achievement of 80 or 160 mL/kg/day. Outcomes included weight, protein intake, biochemical markers, feeding intolerance, and length of stay (LOS). F80 nutrient supplements commenced before F160 (2.8 vs. 6.7 days, p < 0.0001) and lasted longer (15.2 vs. 12.2 days, p < 0.03). Weight gain velocity and LOS were similar. F80 mean protein intake during the first 10 days was higher (3.38 vs. 2.74 g/kg/day, p < 0.0001). There were fewer infants with protein intake <3 g/kg/day in the F80 group (8% vs. 65%, p < 0001). F80 babies regained birthweight almost two days earlier (7.5 vs. 9.4 days, p < 0.01). Weight gain Z-scores revealed an attenuation of the trend towards lower weight percentiles in the F80 group. Feeding intolerance was decreased for F80 (24.4% vs. 47.6%, p < 0.03). There were no adverse outcomes. Earlier nutrient supplementation for LBW babies lifts mean protein intake to above 3 g/kg/day and reduces both the duration of post-birth weight loss and incidence of feeding intolerance.

Protein supplementation of human milk for promoting growth in preterm infants

BACKGROUND

Preterm infants require high protein intake to achieve adequate growth and development. Although breast milk feeding has many benefits for this population, the protein content is highly variable, and inadequate to support rapid infant growth. This is a 2018 update of a Cochrane Review first published in 1999.

OBJECTIVES

To determine whether protein-supplemented human milk compared with unsupplemented human milk, fed to preterm infants, improves growth, body composition, cardio-metabolic, and neurodevelopmental outcomes, without significant adverse effects.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search CENTRAL, MEDLINE via PubMed, Embase, and CINAHL (February 2018). We also searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials (RCT) and quasi-randomised trials.

SELECTION CRITERIA

Published and unpublished RCTs were eligible if they used random or quasi-random methods to allocate hospitalised preterm infants who were being fed human milk, to additional protein supplementation or no supplementation.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data, assessed risk of bias and the quality of evidence at the outcome level, using GRADE methodology. We performed meta-analyses, using risk ratio (RR) for dichotomous data, and mean difference (MD) for continuous data, with their respective 95% confidence intervals (CIs). We used a fixed-effect model and had planned to explore potential causes of heterogeneity via subgroup or sensitivity analyses.

MAIN RESULTS

We included six RCTs, involving 204 preterm infants. Low-quality evidence showed that protein supplementation of human milk increased in-hospital rates of growth in weight (MD 3.82 g/kg/day, 95% CI 2.94 to 4.7; five RCTs, 101 infants; I² = 73%), length (MD 0.12 cm/wk, 95% CI 0.07 to 0.17; four RCTs, 68 infants; I² = 89%), and head circumference (MD 0.06 cm/wk, 95% CI 0.01 to 0.12; four RCTs, 68 infants; I² = 84%). There was no evidence of a clear difference in rate of growth of skin fold thickness between the supplemented and unsupplemented groups (triceps MD 0.06 mm/wk, 95% CI -0.09 to 0.21; one RCT, 20 infants; or subscapular MD 0.00 mm/wk, 95% CI -0.17 to 0.17; one RCT, 20 infants). Protein supplementation led to longer hospital stays (MD 18.5 days, 95% CI 4.39 to 32.61; one RCT, 20 infants; very low-quality evidence), and higher blood urea nitrogen concentrations compared to the unsupplemented group (MD 0.95 mmol/L, 95% CI 0.81 to 1.09; four RCTs, 81 infants; I² = 56%). Very low-quality evidence did not show that protein supplementation clearly increased the risk of feeding intolerance (RR 2.70, 95% CI 0.13 to 58.24; one RCT, 17 infants), or necrotizing enterocolitis (RR 1.11, 95% CI 0.07 to 17.12; one RCT, 76 infants), or clearly altered serum albumin concentrations (MD 2.5 g/L, 95% CI -5.66 to 10.66; one RCT, 11 infants), compared with the unsupplemented groups. No data were available about the effects of protein supplementation on long-term growth, body mass index, body composition, neurodevelopmental, or cardio-metabolic outcomes.

AUTHORS' CONCLUSIONS

Low-quality evidence showed that protein supplementation of human milk, fed to preterm infants, increased short-term growth. However, the small sample sizes, low precision, and very low-quality evidence regarding duration of hospital stay, feeding intolerance, and necrotising enterocolitis precluded any conclusions about these outcomes. There were no data on outcomes after hospital discharge. Our findings may not be generalisable to low-resource settings, as none of the included studies were conducted in these settings.Since protein supplementation of human milk is now usually done as a component of multi-nutrient fortifiers, future studies should compare different amounts of protein in multi-component fortifiers, and be designed to determine the effects on duration of hospital stay and safety, as well as on long-term growth, body composition, cardio-metabolic, and neurodevelopmental outcomes.

Donor Human Milk Protects against Bronchopulmonary Dysplasia: A Systematic Review and Meta-Analysis

Bronchopulmonary dysplasia (BPD) is the most common complication after preterm birth. Pasteurized donor human milk (DHM) has increasingly become the standard of care for very preterm infants over the use of preterm formula (PF) if the mother's own milk (MOM) is unavailable. Studies have reported beneficial effects of DHM on BPD. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies on the effects of DHM on BPD and other respiratory outcomes. Eighteen studies met the inclusion criteria. Meta-analysis of RCTs could not demonstrate that supplementation of MOM with DHM reduced BPD when compared to PF (three studies, risk ratio (RR) 0.89, 95% confidence interval (CI) 0.60-1.32). However, meta-analysis of observational studies showed that DHM supplementation reduced BPD (8 studies, RR 0.78, 95% CI 0.67-0.90). An exclusive human milk diet reduced the risk of BPD, compared to a diet with PF and/or bovine milk-based fortifier (three studies, RR 0.80, 95% CI 0.68-0.95). Feeding raw MOM, compared to feeding pasteurized MOM, protected against BPD (two studies, RR 0.77, 95% CI 0.62-0.96). In conclusion, our data suggest that DHM protects against BPD in very preterm infants.

Growth and Nutritional Biomarkers of Preterm Infants Fed a New Powdered Human Milk Fortifier: A Randomized Trial

OBJECTIVES

The aim of this study was to assess growth and nutritional biomarkers of preterm infants fed human milk (HM) supplemented with a new powdered HM fortifier (nHMF) or a control HM fortifier (cHMF). The nHMF provides similar energy content, 16% more protein (partially hydrolyzed whey), and higher micronutrient levels than the cHMF, along with medium-chain triglycerides and docosahexaenoic acid.

METHODS

In this controlled, multicenter, double-blind study, a sample of preterm infants ≤32 weeks or ≤1500 g were randomized to receive nHMF (n = 77) or cHMF (n = 76) for a minimum of 21 days. Weight gain was evaluated for noninferiority (margin = -1 g/day) and superiority (margin = 0 g/day). Nutritional status and gut inflammation were assessed by blood, urine, and fecal biochemistries. Adverse events were monitored.

RESULTS

Adjusted mean weight gain (analysis of covariance) was 2.3 g/day greater in nHMF versus cHMF; the lower limit of the 95% CI (0.4 g/day) exceeded both noninferiority (P < 0.001) and superiority margins (P = 0.01). Weight gain rate (unadjusted) was 18.3 (nHMF) and 16.8 g · kg · day (cHMF) between study days 1 and 21 (D1-D21). Length and head circumference (HC) gains between D1 and D21 were not different. Adjusted weight-for-age z score at D21 and HC-for-age z score at week 40 corrected age were greater in nHMF versus cHMF (P = 0.013, P = 0.003 respectively). nHMF had higher serum blood urea nitrogen, pre-albumin, alkaline phosphatase, and calcium (all within normal ranges; all P ≤ 0.019) at D21 versus cHMF. Both HMFs were well tolerated with similar incidence of gastrointestinal adverse events.

CONCLUSIONS

nHMF providing more protein and fat compared to a control fortifier is safe, well-tolerated, and improves the weight gain of preterm infants.

The effects of human milk fortification on nutrients and milk properties

OBJECTIVE

To investigate the effects of fortification and storage on nutrients and properties of various human milk (HM) types.

STUDY DESIGN

Mother's own milk (MOM) and pasteurized donor human milk (DHM; n=118) were analyzed pre- and post fortification with Enfamil and Similac human milk fortifier (EHMF and SHMF) before and after 24 h of refrigerated storage.

RESULTS

Milk fortified with SHMF had significantly greater osmolality, pH and lipase activity than EHMF. Changes in protein, pH and osmolality following refrigerated storage differed between fortifiers. When milk type was factored into the analysis, protein and lipase activity changes in fresh MOM differed significantly from DHM and frozen MOM. Analysis of UNF HM found higher protein levels in preterm vs term samples and in MOM vs DHM.

CONCLUSION

Nutrient composition of HM varies significantly by milk type. Although fortifiers enhance select nutrients, each has the potential to affect HM properties in a unique way and these affects may vary by milk type.

Clinical and nutritional outcomes of two liquid human milk fortifiers for premature infants

BACKGROUND

In preterm infants fortification of human milk with human milk fortifiers (HMF) to optimize nutrition and growth is standard practice. We compared clinical, nutrition and growth outcomes in infants receiving two types of liquid HMF (LHMF).

METHODS

Clinical, nutrition and growth outcomes were compared between infants admitted to a level IV NICU, and born with birth weight less than or equal to 1800 grams, between 10/1/2014-12/31/2014 and received human milk with acidified LHMF (ALHMF) and between 1/1/2015-4/31/2015 and received human milk with heat treated LHMF (HTLHMF).

RESULTS

Of the 85 qualifying infants, 67 received human milk and LHMF. ALHMF group had significantly higher incidence of metabolic acidosis and lower bicarbonate and base excess levels relative to infants receiving HTLHMF (P < 0.001). There were no significant differences by LHMF status in other clinical outcomes and nutrition and growth outcomes. In multivariate analyses, ALHMF use was associated with metabolic acidosis, and lower base excess and bicarbonate levels.

CONCLUSION

In our study, the clinical, nutrition and growth outcomes between the two LHMF groups were similar. However, use of ALHMF in preterm infants was associated with increased incidence of metabolic acidosis in our cohort. Further randomized control trials are warranted to evaluate these findings.

Trend of Nutritional Support in Preterm Infants

Without appropriate nutritional support, preterm infants fail to grow after birth and have malnutrition. The main reason for delayed feeding is fear of immaturity of gastrointestinal function. The principles of nutritional practice should be as follows: (1) minimal early initiation of enteral feeding with breast milk (0.5-1 mL/h) to start on Day 1 if possible and gradual increase as tolerated; (2) early aggressive parenteral nutrition as soon as possible; (3) provision of lipids at rates that will meet the additional energy needs of about 2-3 g/kg/d; and (4) attempt to increase enteral feeding rather than parenteral nutrition.

Comparison of a Powdered, Acidified Liquid, and Non-Acidified Liquid Human Milk Fortifier on Clinical Outcomes in Premature Infants

We previously compared infant outcomes between a powdered human milk fortifier (P-HMF) vs. acidified liquid HMF (AL-HMF). A non-acidified liquid HMF (NAL-HMF) is now commercially available. The purpose of this study is to compare growth and outcomes of premature infants receiving P-HMF, AL-HMF or NAL-HMF. An Institutional Review Board (IRB) approved retrospective chart review compared infant outcomes (born < 2000 g) who received one of three HMF. Growth, enteral nutrition, laboratory and demographic data were compared. 120 infants were included (P-HMF = 46, AL-HMF = 23, NAL-HMF = 51). AL-HMF infants grew slower in g/day (median 23.66 vs. P-HMF 31.27, NAL-HMF 31.74 (p < 0.05)) and in g/kg/day, median 10.59 vs. 15.37, 14.03 (p < 0.0001). AL-HMF vs. NAL-HMF infants were smaller at 36 weeks gestational age (median 2046 vs. 2404 g, p < 0.05). However AL-HMF infants received more daily calories (p = 0.21) and protein (p < 0.0001), mean 129 cal/kg, 4.2 g protein/kg vs. P-HMF 117 cal/kg, 3.7 g protein/kg , NAL-HMF 120 cal/kg, 4.0 g protein/kg. AL-HMF infants exhibited lower carbon dioxide levels after day of life 14 and 30 (p < 0.0001, p = 0.0038). Three AL-HMF infants (13%) developed necrotizing enterocolitis (NEC) vs. no infants in the remaining groups (p = 0.0056). A NAL-HMF is the most optimal choice for premature human milk-fed infants in a high acuity neonatal intensive care unit (NICU).

Growth and Tolerance of Preterm Infants Fed a New Extensively Hydrolyzed Liquid Human Milk Fortifier

OBJECTIVES

This study was a comparison of growth and tolerance in premature infants fed either standard powdered human milk fortifier (HMF) or a newly formulated concentrated liquid that contained extensively hydrolyzed protein.

METHODS

This was an unblinded randomized controlled multicenter noninferiority study on preterm infants receiving human milk (HM) supplemented with 2 randomly assigned HMFs, either concentrated liquid HMF containing extensively hydrolyzed protein (LE-HMF) or a powdered intact protein HMF (PI-HMF) as the control. The study population consisted of preterm infants ≤33 weeks who were enterally fed HM. Infants were studied from the first day of HM fortification until day 29 or hospital discharge, whichever came first.

RESULTS

A total of 147 preterm infants were enrolled. Noninferiority was observed in weight gain reported in the intent-to-treat (ITT) analysis was 18.2 and 17.5 g · kg(-1) · day(-1) for the LE-HMF and PI-HMF groups, respectively. In an a priori defined subgroup of strict protocol followers (n = 75), the infants fed LE-HMF achieved greater weight over time than those fed PI-HMF (P = 0.036). The LE-HMF group achieved greater linear growth over time compared to the PI-HMF (P = 0.029). The protein intake from fortified HM was significantly higher in the LE-HMF group compared with the PI-HMF group (3.9 vs 3.3 g · kg(-1) · day(-1), P < 0.0001). Both fortifiers were well tolerated with no significant differences in overall morbidity.

CONCLUSIONS

Both fortifiers showed excellent weight gain (grams per kilograms per day), tolerance, and low incidence of morbidity outcomes with the infants who were strict protocol followers fed LE-HMF having improved growth during the study. These data point to the safety and suitability of this new concentrated liquid HMF (LE-HMF) in preterm infants. Growth with this fortifier closely matches the recent recommendations for a weight gain of >18 g · kg(-1) · day(-1).

Challenges in breast milk fortification for preterm infants

PURPOSE OF REVIEW

To outline new evidence published from 2013 to 2014 about breast milk fortification in preterm infants.

RECENT FINDINGS

Breast milk is the feeding choice for preterm infants because of its immunoprotective properties. However, breast milk's nutrient content is not sufficient for preterm infants, and interindividual variation is high. The variation challenges standard fortification, which assumes a standard breast milk composition. Two new fortification strategies (adjustable fortification and target fortification) optimize macronutrient intake and improve growth. Adjustable fortification uses blood urea nitrogen levels to adjust fortifier strength. Target fortification analyzes breast milk and fortifies macronutrients individually to achieve targeted intake. Its feasibility is shown in clinical routine. Current breast milk analyzers used for target fortification achieve acceptable precision for protein and fat but not for lactose and energy. Evidence of benefits for postdischarge breast milk fortification is lacking. Eliminating cow's milk products and feeding exclusively breast milk may decrease the occurrence of feeding intolerance and necrotizing enterocolitis. To facilitate exclusively breast milk diets, a collaboration of prenatal, nutrition and lactation stakeholders is key. Fortification increases osmolality; however, safety cutoffs to prevent necrotizing enterocolitis are unclear. There is also new evidence that composition and structure of various macronutrients and micronutrients affect growth and development, and might play a role in future fortification concepts.

SUMMARY

Recent research focuses on the variability of breast milk composition, its impact on postnatal growth patterns and the usefulness of target fortification. As well, diets exclusively composed of human milk are a promising approach to improve feeding tolerance. For safe fortification, osmolality cutoff levels are needed.

Association of metabolic acidosis with bovine milk-based human milk fortifiers

OBJECTIVE

To compare the incidence of metabolic acidosis and feeding intolerance associated with powdered or acidified liquid human milk fortifier (HMF).

STUDY DESIGN

This retrospective study evaluated infants ⩽ 32 weeks gestational age or ⩽ 1500 g birth weight who received human milk with either powdered or acidified liquid HMF (50 consecutively born infants per group). Primary outcomes tracked were metabolic acidosis (base excess less than -4 mmol l(-1) or bicarbonate less than 18 mmol l(-1)), feeding intolerance (gastric residual > 50% feed volume, > 3 loose stools or emesis per day, abdominal tenderness or distention), necrotizing enterocolitis, late-onset infection, death, length of hospital stay and ability to remain on HMF. Demographics, feeding practices, growth parameters and laboratory data were also collected.

RESULT

Significantly more infants who received acidified liquid HMF developed metabolic acidosis (P < 0.001). Base excess and bicarbonate were both significantly decreased after HMF addition in the liquid HMF group (base excess P = 0.006, bicarbonate P < 0.001). More infants were switched off liquid HMF due to metabolic acidosis or feeding intolerance than those on powdered HMF (P < 0.001). Despite increased protein intake in the liquid HMF group (P = 0.009), both groups had similar enteral caloric intakes with no difference in growth rates between the two groups. There was no significant difference in any of the other primary outcomes.

CONCLUSION

Infants receiving acidified liquid human milk fortifier were more likely to develop metabolic acidosis and to be switched off HMF than those who received powdered HMF. Growth in the liquid HMF group was no different than the powdered group, despite higher protein intake.

Considerations in meeting protein needs of the human milk-fed preterm infant

Preterm infants provided with sufficient nutrition to achieve intrauterine growth rates have the greatest potential for optimal neurodevelopment. Although human milk is the preferred feeding for preterm infants, unfortified human milk provides insufficient nutrition for the very low-birth-weight infant. Even after fortification with human milk fortifier, human milk often fails to meet the high protein needs of the smallest preterm infants, and additional protein supplementation must be provided. Although substantial evidence exists to support quantitative protein goals for human milk-fed preterm infants, the optimal type of protein for use in human milk fortification remains uncertain. This question was addressed through a PubMed literature search of prospective clinical trials conducted since 1990 in preterm or low-birth-weight infant populations. The following 3 different aspects of protein quality were evaluated: whey-to-casein ratio, hydrolyzed versus intact protein, and bovine milk protein versus human milk protein. Because of a scarcity of current studies conducted with fortified human milk, studies examining protein quality using preterm infant formulas were included to address certain components of the clinical question. Twenty-six studies were included in the review study. No definite advantage was found for any specific whey-to-casein ratio. Protein hydrolyzate products with appropriate formulations can support adequate growth and biochemical indicators of nutrition status and may reduce gastrointestinal transit time, gastroesophageal reflux events, and later incidence of atopic dermatitis in some infants. Plasma amino acid levels similar to those of infants fed exclusive human milk-based diets can be achieved with products composed of a mixture of bovine proteins, peptides, and amino acids formulated to replicate the amino acid composition of human milk. Growth and biochemical indicators of nutrition status are similar for infants fed human milk fortified with human milk protein and bovine milk protein.

Evidence-based feeding strategies before and after the development of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants and is associated with significant morbidity and mortality. While the pathogenesis of NEC remains incompletely understood, it is well established that the risk of disease is increased by the administration of infant formula and decreased by the administration of breast milk. This review will focus on the mechanisms by which breast milk may serve to protect against NEC, and will review the evidence regarding various feeding strategies that may be utilized before and after an episode of NEC.

High-protein formulas: evidence for use in preterm infants

Relatively high amounts of protein are required to achieve normal fractional protein synthetic rates during the late second through early third trimester of fetal growth. Once preterm infants achieve higher protein intakes for sustained periods, growth begins to approximate that of the normally growing fetus and long-term neurodevelopmental outcomes are improved. Preterm formulas have been developed that are enriched in protein. This review discusses several factors when using standard preterm formulas and high-protein preterm formulas in the neonatal intensive care unit, with an emphasis on quantity and quality of enteral protein delivery and risks to insufficient and/or excess protein administration.