Comparison of the Effect of Three Different Fortification Methods on Growth of Very Low Birth Weight Infants

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.

Human Milk Fortification for Very Preterm Infants: Toward Optimal Nutrient Delivery, Neonatal Intensive Care Unit Growth, and Long-Term Outcomes

Human milk is the preferred diet for very preterm infants due to short-term and long-term benefits for health and neurodevelopment. Fortification of human milk is required to deliver sufficient nutrients to attain recommended growth targets during the neonatal hospitalization. Intrinsic variability in human milk composition poses a challenge in clinical practice because some infants fail to meet recommended nutrient intakes even with existing approaches of standard (fixed-dose) and adjustable fortification. Individually targeted fortification is an emerging strategy to minimize nutrition delivery gaps through application of point-of-care human milk analysis and has potential to improve growth and related outcomes.

Individualized Fortification Based on Measured Macronutrient Content of Human Milk Improves Growth and Body Composition in Infants Born Less than 33 Weeks: A Mixed-Cohort Study

The optimal method for human milk (HM) fortification has not yet been determined. This study assessed whether fortification relying on measured HM macronutrient content (Miris AB analyzer, Upsala, Sweden) composition is superior to fortification based on assumed HM macronutrient content, to optimize the nutrition support, growth, and body composition in infants born at <33 weeks' gestation. In a mixed-cohort study, 57 infants fed fortified HM based on its measured content were compared with 58 infants fed fortified HM based on its assumed content, for a median of 28 and 23 exposure days, respectively. The ESPGHAN 2010 guidelines for preterm enteral nutrition were followed. Growth assessment was based on body weight, length, and head circumference Δ z-scores, and the respective growth velocities until discharge. Body composition was assessed using air displacement plethysmography. Fortification based on measured HM content provided significantly higher energy, fat, and carbohydrate intakes, although with a lower protein intake in infants weighing ≥ 1 kg and lower protein-to-energy ratio in infants weighing < 1 kg. Infants fed fortified HM based on its measured content were discharged with significantly better weight gain, length, and head growth. These infants had significantly lower adiposity and greater lean mass near term-equivalent age, despite receiving higher in-hospital energy and fat intakes, with a mean fat intake higher than the maximum recommended and a median protein-to-energy ratio intake (in infants weighing < 1 kg) lower than the minimum recommended.

Enteral Nutrition in Preterm Infants (2022): A Position Paper From the ESPGHAN Committee on Nutrition and Invited Experts

OBJECTIVES

To review the current literature and develop consensus conclusions and recommendations on nutrient intakes and nutritional practice in preterm infants with birthweight <1800 g.

METHODS

The European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee of Nutrition (CoN) led a process that included CoN members and invited experts. Invited experts with specific expertise were chosen to represent as broad a geographical spread as possible. A list of topics was developed, and individual leads were assigned to topics along with other members, who reviewed the current literature. A single face-to-face meeting was held in February 2020. Provisional conclusions and recommendations were developed between 2020 and 2021, and these were voted on electronically by all members of the working group between 2021 and 2022. Where >90% consensus was not achieved, online discussion meetings were held, along with further voting until agreement was reached.

RESULTS

In general, there is a lack of strong evidence for most nutrients and topics. The summary paper is supported by additional supplementary digital content that provide a fuller explanation of the literature and relevant physiology: introduction and overview; human milk reference data; intakes of water, protein, energy, lipid, carbohydrate, electrolytes, minerals, trace elements, water soluble vitamins, and fat soluble vitamins; feeding mode including mineral enteral feeding, feed advancement, management of gastric residuals, gastric tube placement and bolus or continuous feeding; growth; breastmilk buccal colostrum, donor human milk, and risks of cytomegalovirus infection; hydrolyzed protein and osmolality; supplemental bionutrients; and use of breastmilk fortifier.

CONCLUSIONS

We provide updated ESPGHAN CoN consensus-based conclusions and recommendations on nutrient intakes and nutritional management for preterm infants.

Effect of Targeted vs. Standard Fortification of Breast Milk on Growth and Development of Preterm Infants (≤32 Weeks): Results from an Interrupted Randomized Controlled Trial

Human milk is recommended for very low birth weight infants. Their nutritional needs are high, and the fortification of human milk is a standard procedure to optimize growth. Targeted fortification accounts for the variability in human milk composition. It has been a promising alternative to standard fixed-dose fortification, potentially improving short-term growth. In this trial, preterm infants (≤32 weeks of gestation) were randomized to receive human milk after standard fortification (HMF, Nutricia) or tailored fortification with modular components of proteins (Bebilon Bialko, Nutricia), carbohydrates (Polycal, Nutricia), and lipids (Calogen, Nutricia). The intervention started when preterms reached 80 mL/kg/day enteral feeds. Of the target number of 220 newborns, 39 were randomized. The trial was interrupted due to serious intolerance in five cases. There was no significant difference in velocity of weight gain during the supplementation period (primary outcome) in the tailored vs. standard fortification group: 27.01 ± 10.19 g/d vs. 25.84 ± 13.45 g/d, p = 0.0776. Length and head circumference were not significantly different between the groups. We found the feasibility of targeted fortification to be limited in neonatal intensive care unit practice. The trial was registered at clinicaltrials.gov NCT:03775785.

Expressed Breast Milk Analysis: Role of Individualized Protein Fortification to Avoid Protein Deficit After Preterm Birth and Improve Infant Outcomes

Background: Expressed breast milk (EBM) protein content is highly variable between mothers and often below published values that are still used for EBM protein fortification strategies. This approach may result in significant protein deficit and suboptimal protein energy (P/E) ratio. The study aim was to determine whether individualized EBM protein analysis and fortification will reduce preterm infant protein deficits and improve growth and neurodevelopmental outcome. Study Methods: In a single-center randomized, blinded study of infants born at 24 0/7-29 6/7 weeks, mother-specific protein values measured by a milk analyzer were used to individualize infant-specific protein intake (interventional group, IG), and compared this to a standardized protein fortification scheme based on published values of EBM protein content of 1.4 g/dL (control group, CG). For IG, milk analyzer protein values of mother's EBM were used to adjust protein content of the EBM. The CG EBM protein content was adjusted using the standard published value of 1.4 g/dL and not based on milk analyzer values. EBM protein content, protein intake, protein/energy (P/E) ratio, weight (WT), head circumference (HC), length (L), growth velocity (GV) from 2 to 6 weeks of age, WT, HC and L Z-Scores at 32- and 35-weeks PMA, and lean body mass (35 weeks PMA skin fold thickness) were measured. Neurodevelopment was assessed by Bayley III at average 24 months corrected gestational age (CGA). Results: EBM protein content before fortification was significantly below published values of 1.4 g/dL at all time points in both CG and IG. CG protein deficit was significantly decreased and progressively worsened throughout the study. Individualized protein fortification in IG avoided protein deficit and optimized P/E ratio. Although no significant change in short-term GV (at 6 weeks of age) was seen between groups, IG infants born at <27 weeks had significant improvements in WT and L z-scores, and leaner body mass at 32 and 35 weeks PMA. IG exhibited significantly improved cognitive scores at 24 months CGA. Conclusions: Infant-specific protein supplementation of mother's EBM optimized P/E ratio by eliminating protein deficit and improved growth z scores at 32- and 35-weeks PMA and neurocognitive testing at 24 months.

Using Nature to Nurture: Breast Milk Analysis and Fortification to Improve Growth and Neurodevelopmental Outcomes in Preterm Infants

Premature infants are born prior to a critical window of rapid placental nutrient transfer and fetal growth-particularly brain development-that occurs during the third trimester of pregnancy. Subsequently, a large proportion of preterm neonates experience extrauterine growth failure and associated neurodevelopmental impairments. Human milk (maternal or donor breast milk) is the recommended source of enteral nutrition for preterm infants, but requires additional fortification of macronutrient, micronutrient, and energy content to meet the nutritional demands of the preterm infant in attempts at replicating in utero nutrient accretion and growth rates. Traditional standardized fortification practices that add a fixed amount of multicomponent fortifier based on assumed breast milk composition do not take into account the considerable variations in breast milk content or individual neonatal metabolism. Emerging methods of individualized fortification-including targeted and adjusted fortification-show promise in improving postnatal growth and neurodevelopmental outcomes in preterm infants.

Promoting Human Milk and Breastfeeding for the Very Low Birth Weight Infant

Provision of mother's own milk for hospitalized very low birth weight (VLBW) (≤1500 g) infants in the NICU provides short- and long-term health benefits. Mother's own milk, appropriately fortified, is the optimal nutrition source for VLBW infants. Every mother should receive information about the critical importance of mother's own milk to the health of a VLBW infant. Pasteurized human donor milk is recommended when mother's own milk is not available or sufficient. Neonatal health care providers can support lactation in the NICU and potentially reduce disparities in the provision of mother's own milk by providing institutional supports for early and frequent milk expression and by promoting skin-to-skin contact and direct breastfeeding, when appropriate. Promotion of human milk and breastfeeding for VLBW infants requires multidisciplinary and system-wide adoption of lactation support practices.

Exploring Innovations in Human Milk Analysis in the Neonatal Intensive Care Unit: A Survey of the United States

Introduction: Human milk (HM) is the ideal enteral feeding for nearly all infants and offers unique benefits to the very low birthweight (VLBW) infant population. It is a challenge to meet the high nutrient requirements of VLBW infants due to the known variability of HM composition. Human milk analysis (HMA) assesses the composition of HM and allows for individualized fortification. Due to recent U.S. Food and Drug Administration (FDA) approval, it has relatively recent availability for clinical use in the US.

Aim: To identify current practices of HMA and individualized fortification in neonatal intensive care units (NICUs) across the United States (US) and to inform future translational research efforts implementing this nutrition management method.

Methods: An institutional review board (IRB) approved survey was created and collected data on the following subjects such as NICU demographics, feeding practices, HM usage, HM fortification practices, and HMA practices. It was distributed from 10/30–12/21/2020 via online pediatric nutrition groups and listservs selected to reach the intended audience of NICU dietitians and other clinical staff. Each response was assessed prior to inclusion, and descriptive analysis was performed.

Results: About 225 survey responses were recorded during the survey period with 119 entries included in the analysis. This represented 36 states and Washington D.C., primarily from level III and IV NICUs. HMA was reported in 11.8% of responding NICUs. The most commonly owned technology for HMA is the Creamatocrit Plus TM (EKF Diagnostics), followed by the HM Analyzer by Miris (Uppsala, Sweden). In NICUs practicing HMA, 84.6% are doing so clinically.

Discussion: Feeding guidelines and fortification of HM remain standard of care, and interest in HMA was common in this survey. Despite the interest, very few NICUs are performing HMA and individualized fortification. Barriers identified include determining who should receive individualized fortification and how often, collecting a representative sample, and the cost and personnel required.

Conclusions: Human milk analysis and individualized fortification are emerging practices within NICUs in the US. Few are using it in the clinical setting with large variation in execution among respondents and many logistical concerns regarding implementation. Future research may be beneficial to evaluate how practices change as HMA and individualized fortification gain popularity and become more commonly used in the clinical setting.

Protein Enrichment of Donor Breast Milk and Impact on Growth in Very Low Birth Weight Infants

Protein content is often inadequate in donor breast milk (DBM), resulting in poor growth. The use of protein-enriched target-pooled DBM (DBM+) has not been examined. We compared three cohorts of very low birth weight (VLBW) infants, born ≤ 1500 g: DBM cohort receiving > 1-week target-pooled DBM (20 kcal/oz), MBM cohort receiving ≤ 1-week DBM, and DBM+ cohort receiving > 1-week DBM+. Infants followed a standardized feeding regimen with additional fortification per clinical discretion. Growth velocities and z-scores were calculated for the first 4 weeks (n = 69 for DBM, 71 for MBM, 70 for DBM+) and at 36 weeks post-menstrual age (n = 58, 64, 59, respectively). In total, 60.8% MBM infants received fortification >24 kcal/oz in the first 30 days vs. 78.3% DBM and 77.1% DBM+. Adjusting for SGA, length velocity was greater with DBM+ than DBM in week 1. Average weight velocity and z-score change were improved with MBM compared to DBM and DBM+, but length z-score decreased similarly across all groups. Incidences of NEC and feeding intolerance were unchanged between eras. Thus, baseline protein enrichment appears safe in stable VLBW infants. Weight gain is greatest with MBM. Linear growth comparable to MBM is achievable with DBM+, though the overall length trajectory remains suboptimal.

Preterm infant nutrition and growth with a human milk diet

Human milk is the preferred enteral diet for preterm infants. It provides macronutrients, micronutrients, and bioactive factors that support physical growth and neurodevelopment. Challenges of the human milk diet include the variability in its composition and a need for fortification to mirror placental nutrient delivery and prevent extrauterine growth restriction. Various strategies exist to attain target nutrient provision and optimize growth, including leveraging new technology for point-of-care human milk analysis. When maternal milk is unavailable or in short supply, pasteurized donor human milk is the preferred alternative. Infants fed donor milk may have slower weight gain than those fed exclusively maternal milk or formula, whereas infants fed fortified maternal milk have similar weight gain to preterm formula-fed infants. Future directions include more rigorous characterization of the variation in human milk, further investigation of the clinical benefits of non-nutrient bioactive factors in milk, and novel approaches to optimize fortification.

Customized Human Milk Fortification Based on Measured Human Milk Composition to Improve the Quality of Growth in Very Preterm Infants: A Mixed-Cohort Study Protocol

Adequate nutrition of very preterm infants comprises fortification of human milk (HM), which helps to improve their nutrition and health. Standard HM fortification involves a fixed dose of a multi-nutrient HM fortifier, regardless of the composition of HM. This fortification method requires regular measurements of HM composition and has been suggested to be a more accurate fortification method. This observational study protocol is designed to assess whether the target HM fortification method (contemporary cohort) improves the energy and macronutrient intakes and the quality of growth of very preterm infants, compared with the previously used standard HM fortification (historical cohorts). In the contemporary cohort, a HM multi-nutrient fortifier and modular supplements of protein and fat are used for HM fortification, and the enteral nutrition recommendations of the European Society for Paediatric Gastroenterology Hepatology and Nutrition for preterm infants will be considered. For both cohorts, the composition of HM is assessed using the Miris Human Milk analyzer (Uppsala, Sweden). The quality of growth will be assessed by in-hospital weight, length, and head circumference growth velocities and a single measurement of adiposity (fat mass percentage and fat mass index) performed just after discharge, using the air displacement plethysmography method (Pea Pod, Cosmed, Italy). ClinicalTrials.gov registration number: NCT04400396.

Individualized versus standard diet fortification for growth and development in preterm infants receiving human milk

BACKGROUND

Human milk as compared to formula reduces morbidity in preterm infants but requires fortification to meet their nutritional needs and to reduce the risk of extrauterine growth failure. Standard fortification methods are not individualized to the infant and assume that breast milk is uniform in nutritional content. Strategies for individualizing fortification are available; however it is not known whether these are safe, or if they improve outcomes in preterm infants.

OBJECTIVES

To determine whether individualizing fortification of breast milk feeds in response to infant blood urea nitrogen (adjustable fortification) or to breast milk macronutrient content as measured with a milk analyzer (targeted fortification) reduces mortality and morbidity and promotes growth and development compared to standard, non-individualized fortification for preterm infants receiving human milk at < 37 weeks' gestation or at birth weight < 2500 grams.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 9), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on September 20, 2019. We also searched clinical trials databases and the reference lists of retrieved articles for pertinent randomized controlled trials (RCTs) and quasi-randomized trials.

SELECTION CRITERIA

We considered randomized, quasi-randomized, and cluster-randomized controlled trials of preterm infants fed exclusively breast milk that compared a standard non-individualized fortification strategy to individualized fortification using a targeted or adjustable strategy. We considered studies that examined any use of fortification in eligible infants for a minimum duration of two weeks, initiated at any time during enteral feeding, and providing any regimen of human milk feeding.

DATA COLLECTION AND ANALYSIS

Data were collected using the standard methods of Cochrane Neonatal. Two review authors evaluated the quality of the studies and extracted data. We reported analyses of continuous data using mean differences (MDs), and dichotomous data using risk ratios (RRs). We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Data were extracted from seven RCTs, resulting in eight publications (521 total participants were enrolled among these studies), with duration of study interventions ranging from two to seven weeks. As compared to standard non-individualized fortification, individualized (targeted or adjustable) fortification of enteral feeds probably increased weight gain during the intervention (typical mean difference [MD] 1.88 g/kg/d, 95% confidence interval [CI] 1.26 to 2.50; 6 studies, 345 participants), may have increased length gain during the intervention (typical MD 0.43 mm/d, 95% CI 0.32 to 0.53; 5 studies, 242 participants), and may have increased head circumference gain during the intervention (typical MD 0.14 mm/d, 95% CI 0.06 to 0.23; 5 studies, 242 participants). Compared to standard non-individualized fortification, targeted fortification probably increased weight gain during the intervention (typical MD 1.87 g/kg/d, 95% CI 1.15 to 2.58; 4 studies, 269 participants) and may have increased length gain during the intervention (typical MD 0.45 mm/d, 95% CI 0.32 to 0.57; 3 studies, 166 participants). Adjustable fortification probably increased weight gain during the intervention (typical MD 2.86 g/kg/d, 95% CI 1.69 to 4.03; 3 studies, 96 participants), probably increased gain in length during the intervention (typical MD 0.54 mm/d, 95% CI 0.38 to 0.7; 3 studies, 96 participants), and increased gain in head circumference during the intervention (typical MD 0.36 mm/d, 95% CI 0.21 to 0.5; 3 studies, 96 participants). We are uncertain whether there are differences between individualized versus standard fortification strategies in the incidence of in-hospital mortality, bronchopulmonary dysplasia, necrotizing enterocolitis, culture-proven late-onset bacterial sepsis, retinopathy of prematurity, osteopenia, length of hospital stay, or post-hospital discharge growth. No study reported severe neurodevelopmental disability as an outcome. One study that was published after our literature search was completed is awaiting classification.

AUTHORS' CONCLUSIONS

We found moderate- to low-certainty evidence suggesting that individualized (either targeted or adjustable) fortification of enteral feeds in very low birth weight infants increases growth velocity of weight, length, and head circumference during the intervention compared with standard non-individualized fortification. Evidence showing important in-hospital and post-discharge clinical outcomes was sparse and of very low certainty, precluding inferences regarding safety or clinical benefits beyond short-term growth.

Human Milk Supplements: Principles, Practices, and Current Controversies

Human milk is the most optimal source of nutrition for preterm and term infants. However, in most preterm infants, breast milk fails to meet the energy needs of the newborn infant. Overwhelming evidence supports the fortification of breast milk in preterm infants to facilitate better short-term outcomes. Several single-nutrient and multinutrient breast milk supplements and fortifiers are used to improve the macronutrient and micronutrient content of breast milk. An individualized fortification strategy has the potential to offer better results compared with standard fortification strategies. Human milk-derived fortification is promising, but the benefits in exclusively human milk-fed preterm infants are unclear.

Individualized target fortification of breast milk with protein, carbohydrates, and fat for preterm infants: A double-blind randomized controlled trial

BACKGROUND & AIMS

In preterm infants, natural variation of breast milk composition makes it difficult to achieve recommended macronutrient intakes with standard fortification. Evidence suggests that nutritional deficiency induces poor postnatal growth. This study investigates impacts of target fortification on preterm growth and metabolism by adjusting breast milk macronutrients.

METHODS

This study was conducted as a single-centre, double-blind, randomized controlled trial for infants <30 gestational weeks. The control group received standard fortification and the intervention group received standard plus target fortification adding modular protein, lipids, and carbohydrates. Breast milk content was measured 3x/week using a validated near-infrared bedside spectrometer (NIRS). Modulars were added to achieve recommended values. To assess total nutrient intake, all 2810 native breast milk samples were analyzed - protein and fat using bedside-NIRS, lactose using tandem mass spectrometry (UPLC-MS/MS). Body composition was measured using air displacement plethysmography. Primary outcome was weight gain during the first 21 days of intervention.

RESULTS

Baseline characteristics, morbidities, and total fluid intake were not different between groups (intervention n = 52, control n = 51). The intervention group infants had higher macronutrient intakes, weight gain (21.2 ± 2.5 vs 19.3 ± 2.4 g/kg/d, mean difference: 1.9 g/kg/d, 95% CI: 0.9 - 2.9), and body weight. Infants in the intervention group from mothers with below-average breast milk protein content showed greatest impact on weight at 36 weeks (2580 ± 280 g vs 2210 ± 300 g), length, head circumference, fat, and fat-free mass. Also, feeding intolerance was less frequent, blood urea was higher, and triglycerides were lower.

CONCLUSIONS

This study provides evidence that target fortification of breast milk with low macronutrient content enhances the quality of nutrition and growth and is feasible in clinical routine.

Improved growth of extremely and very preterm babies: Evaluation of a quality-of-care initiative

AIM

To measure growth outcomes in preterm infants after introduction of a nutritional care bundle.

METHODS

A total of 509 infants of less than 32 weeks' gestation in a level III neonatal intensive care unit in the UK were studied until they were discharged home. Growth and feeding data were extracted from a prospective data registry for 18 months before and after the intervention. The intervention consisted of earlier routine bovine-derived multi-component fortification once the infant has reached 120ml/kg/day of enteral feed from the first day of life and an exclusive human milk diet with routine bovine-derived multi-component fortification of 120 mL/kg/day.

RESULTS

After the intervention, growth velocity between birth and 28 days increased from 9.7 ± 4.1 to 12.2 ± 4.6 g/kg/day (mean ± standard deviation), and weight z score change decreased from -1.06 ± 0.56 to -0.76 ± 0.59 (P < 0.00002). For the entire group, growth velocity by the discharge home time point increased by 1 g/kg/day. However, the growth velocity of infants who were discharged on an exclusive human milk diet increased the most, from 10.8 ± 2.2 to 13.0 ± 2.8 g/kg/day (P < 0.00001), eliminating the difference seen between these infants and those discharged on infant formula before the intervention.

CONCLUSION

The introduction of a simple nutritional package improved weight gain, particularly in infants fed exclusive human milk at discharge.

Protein intakes to optimize outcomes for preterm infants

Proteins are key structural components of all human cells and are also involved in key physiologic processes through their roles as enzymes, hormones and transport proteins. Protein requirements are substantially higher in preterm infants than those born at term, yet inadequate protein intakes are a common problem on many neonatal units. Very preterm infants (VPT, <32 weeks) commonly receive parenteral amino acid solutions which are typically commenced on admission, and increased over the next few days. Several recent studies have explored differing parenteral amino acid intakes in the first few days, and recommendations have recently been updated. Parenteral nutrition intakes are decreased as enteral feeds are tolerated, but human milk alone will not meet protein needs in most VPT and supplementation or fortification will be required. This review paper considers basic protein and amino acid physiology in the newborn period, and the evidence base for current recommendations.