Enhanced Protein Diet for Preterm Infants: A Prospective, Randomized, Double-blind, Controlled Trial

Eligible Infants Included in Neonatal Clinical Trials and Reasons for Noninclusion: A Systematic Review

Importance

Results of clinical trials can only represent included participants, and many neonatal trials fail due to insufficient participation. Infants not included in research may differ from those included in meaningful ways, biasing the sample and limiting the generalizability of findings.

Objective

To describe the proportion of eligible infants included in neonatal clinical trials and the reasons for noninclusion.

Evidence Review

A systematic search of Cochrane CENTRAL was performed by retrieving articles meeting the following inclusion criteria: full-length, peer-reviewed articles describing clinical trial results in at least 20 human infants from US neonatal intensive care units, published in English, and added to Cochrane CENTRAL between 2017 and 2022. Retrieved articles were screened for inclusion by 2 independent researchers.

Findings

In total 120 articles met inclusion criteria and 91 of these (75.8%) reported the number of infants eligible for participation, which totaled 26 854 in aggregate. Drawing from these, an aggregate of 11 924 eligible infants (44.4%) were included in reported results. Among all eligible infants, most reasons for noninclusion in results were classified as modifiable or potentially modifiable by the research team. Parents declining to participate (8004 infants [29.8%]) or never being approached (2507 infants [9.3%]) were the 2 predominant reasons for noninclusion. Other modifiable reasons included factors related to study logistics, such as failure to appropriately collect data on enrolled infants (859 of 26 854 infants [3.2%]) and other reasons (1907 of 26 854 infants [7.1%]), such as loss to follow-up or eligible participants that were unaccounted for. Nonmodifiable reasons, including clinical change or death, accounted for a small proportion of eligible infants who were not included (858 of 26 854 infants [3.2%]).

Conclusions and Relevance

This systematic review of reporting on eligible infants included and not included in neonatal clinical trials highlights the need for improved documentation on the flow of eligible infants through neonatal clinical trials and may also inform recruitment expectations for trialists designing future protocols. Improved adherence to standardized reporting may clarify which potential participants are being missed, improving understanding of the generalizability of research findings. Furthermore, these findings suggest that future work to understand why parents decline to participate in neonatal research trials and why some are never approached about research may help increase overall participation.

[Expert consensus on enteral nutrition management of preterm infants (2024)]

Providing adequate and balanced nutrition for preterm infants, especially extremely/very preterm infants, is the material basis for promoting their normal growth and development and improving long-term prognosis. Enteral nutrition is the best way to feed preterm infants. Previous systematic reviews have shown that using evidence-based standardized feeding management strategies can effectively promote the establishment of full enteral feeding, reduce the duration of parenteral nutrition, improve the nutritional outcomes of preterm infants, and not increase the risk of necrotizing enterocolitis or death. Based on relevant research in China and overseas, the consensus working group has developed 20 recommendations in 5 aspects including the goal of enteral nutrition, transitioning to enteral nutrition, stable growth period enteral nutrition, supplementation of special nutrients, and monitoring of enteral nutrition for preterm infants, using the Grading of Recommendations Assessment, Development and Evaluation. The aim is to provide recommendations for healthcare professionals involved in the management of enteral nutrition for preterm infants, in order to improve the clinical outcomes of preterm infants.

Race and Ethnicity of Infants Enrolled in Neonatal Clinical Trials: A Systematic Review

Importance

Representativeness of populations within neonatal clinical trials is crucial to moving the field forward. Although racial and ethnic disparities in research inclusion are well documented in other fields, they are poorly described within neonatology.

Objective

To describe the race and ethnicity of infants included in a sample of recent US neonatal clinical trials and the variability in this reporting.

Evidence Review

A systematic search of US neonatal clinical trials entered into Cochrane CENTRAL 2017 to 2021 was conducted. Two individuals performed inclusion determination, data extraction, and quality assessment independently with discrepancies adjudicated by consensus.

Findings

Of 120 studies with 14 479 participants that met the inclusion criteria, 75 (62.5%) included any participant race or ethnicity data. In the studies that reported race and ethnicity, the median (IQR) percentage of participants of each background were 0% (0%-1%) Asian, 26% (9%-42%) Black, 3% (0%-12%) Hispanic, 0% (0%-0%) Indigenous (eg, Alaska Native, American Indian, and Native Hawaiian), 0% (0%-0%) multiple races, 57% (30%-68%) White, and 7% (1%-21%) other race or ethnicity. Asian, Black, Hispanic, and Indigenous participants were underrepresented, while White participants were overrepresented compared with a reference sample of the US clinical neonatal intensive care unit (NICU) population from the Vermont Oxford Network. Many participants were labeled as other race or ethnicity without adequate description. There was substantial variability in terms and methods of reporting race and ethnicity data. Geographic representation was heavily skewed toward the Northeast, with nearly one-quarter of states unrepresented.

Conclusions and Relevance

These findings suggest that neonatal research may perpetuate inequities by underrepresenting Asian, Black, Hispanic, and Indigenous neonates in clinical trials. Studies varied in documentation of race and ethnicity, and there was regional variation in the sites included. Based on these findings, funders and clinical trialists are advised to consider a 3-point targeted approach to address these issues: prioritize identifying ways to increase diversity in neonatal clinical trial participation, agree on a standardized method to report race and ethnicity among neonatal clinical trial participants, and prioritize the inclusion of participants from all regions of the US in neonatal clinical trials.

Clinical Phenotypes of Malnutrition in Young Children: Differential Nutritional Correction

This review article summarizes current data on malnutrition etiology and pathogenesis in infants. Topical requirements for revealing this condition, its diagnosis and severity assessment via centile metrics are presented. The characteristics of the most common clinical phenotypes of postnatal growth insufficiency in infants (premature infants with different degree of maturation, including patients with bronchopulmonary dysplasia) are described. Differential approaches for malnutrition nutritional correction in these children are presented. The final section of the article describes special nutritional needs for children with congenital heart defects in terms of hemodynamic disorders nature and severity. Modern nutritional strategies for preparation of these patients to surgery and for their postoperative period are presented. The use of high-calorie/high-protein product for malnutrition correction in the most vulnerable patients with described in this review phenotypes is worth noticing.

Growth of Very Low Birth Weight Infants Who Received a Liquid Human Milk Fortifier: A Randomized, Controlled Multicenter Trial

OBJECTIVES

To evaluate growth (weight, length, head circumference, and knee-heel length [KHL]) in very low birth weight (VLBW) infants (500-1500 g) who received human milk with a liquid fortifier (LHMF) with high protein and fatty acid content versus a traditional powder fortifier (PHMF) for 45 days or until discharge.

METHODS

This was a multicenter, randomized, controlled trial. An intention-to-treat analysis was performed to determine adverse events and withdrawal causes. We also performed an efficacy analysis involving the infants who completed at least 2 weeks of study.

RESULTS

Of the 158 infants enrolled in the study, 146 completed at least 2 weeks, and 125 completed the entire study. The biodemographic characteristics were similar between groups, with no differences in increments of weight (22.9 vs 22.7 g kg-1 day-1), length (1.03 vs 1.09 cm/week), head circumference (0.91 vs 0.90 cm/week), or KHL (3.6 vs 3.3 mm/week). The KHL increment was greater in infants weighing >1 kg receiving LHMF (3.7 vs 3.2 mm/week, P = 0.027). Although there were no significant differences in serious adverse events, the incidence difference of the composite outcome death/necrotizing enterocolitis between groups warrants attention (1.3% with LHMF and 8.1% with PHMF).

CONCLUSION

There were no differences in the overall growth between VLBW infants receiving either fortifier.

Improving long-term health outcomes of preterm infants: how to implement the findings of nutritional intervention studies into daily clinical practice

Preterm-born children are at risk for later neurodevelopmental problems and cardiometabolic diseases; early-life growth restriction and suboptimal neonatal nutrition have been recognized as risk factors. Prevention of these long-term sequelae has been the focus of intervention studies. High supplies of protein and energy during the first weeks of life (i.e., energy > 100 kcal kg-1 day-1 and a protein-to-energy ratio > 3 g/100 kcal) were found to improve both early growth and later neurodevelopmental outcome. Discontinuation of this high-energy diet is advised beyond 32-34 weeks postconceptional age to prevent excess fat mass and possible later cardiometabolic diseases. After discharge, nutrition with a higher protein-to-energy ratio (i.e., > 2.5-3.0 g/100 kcal) may improve growth and body composition in the short term.Conclusion: Preterm infants in their first weeks of life require a high-protein high-energy diet, starting shortly after birth. Subsequent adjustments in nutritional composition, aimed at achieving optimal body composition and minimizing the long-term cardiometabolic risks without jeopardizing the developing brain, should be guided by the growth pattern. The long-term impact of this strategy needs to be studied. What is Known: • Preterm infants are at risk for nutritional deficiencies and extrauterine growth restriction. • Extrauterine growth restriction and suboptimal nutrition are risk factors for neurodevelopmental problems and cardiometabolic disease in later life. What is New: • Postnatally, a shorter duration of high-energy nutrition may prevent excess fat mass accretion and its associated cardiometabolic risks and an early switch to a protein-enriched diet should be considered from 32-34 weeks postconceptional age. • In case of formula feeding, re-evaluate the need for the continuation of a protein-enriched diet, based on the infant's growth pattern.

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.

Multi-nutrient fortification of human milk for preterm infants

BACKGROUND

Human breast milk-fed preterm infants can accumulate nutrient deficits leading to extrauterine growth restriction. Feeding preterm infants with multi-nutrient fortified human milk could increase nutrient accretion and growth rates and improve neurodevelopmental outcomes. Concern exists, however, that multi-nutrient fortifiers are associated with adverse events such as feed intolerance and necrotising enterocolitis.

OBJECTIVES

To determine whether multi-nutrient fortified human milk, compared with unfortified human milk, affects important outcomes (including growth rate and neurodevelopment) of preterm infants without increasing the risk of adverse effects (such as feed intolerance and necrotising enterocolitis).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 9), MEDLINE via PubMed (1966 to 26 September 2019), Embase (1980 to 26 September 2019), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 26 September 2019). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared feeding preterm infants with multi-nutrient (protein and energy plus minerals, vitamins, or other nutrients) fortified human breast milk versus unfortified (no added protein or energy) breast milk.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratios (RRs), risk differences, and mean differences (MDs). We assessed the certainty of the body of evidence at the outcome level using "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) methods.

MAIN RESULTS

We identified 18 trials in which a total of 1456 preterm infants participated. These trials were generally small and methodologically weak. Meta-analyses provided low- to moderate-certainty evidence showing that multi-nutrient fortification of human milk increases in-hospital rate of weight gain (MD 1.76 g/kg/d, 95% confidence interval (CI) 1.30 to 2.22), body length (MD 0.11 cm/week, 95% CI 0.08 to 0.15), or head circumference (MD 0.06 cm/week, 95% CI 0.03 to 0.08) among preterm infants. Few data on growth and developmental outcomes assessed beyond infancy are available, and these do not show effects of multi-nutrient fortification. The data do not suggest other benefits or harms and provide low-certainty evidence suggesting effects of multi-nutrient fortification on the risk of necrotising enterocolitis in preterm infants (typical RR 1.37, 95% CI 0.72 to 2.63; 13 studies, 1110 infants).

AUTHORS' CONCLUSIONS

Feeding preterm infants with multi-nutrient fortified human breast milk compared with unfortified human breast milk is associated with modest increases in in-hospital growth rates. Evidence is insufficient to show whether multi-nutrient fortification has any effect on long-term growth or neurodevelopment.

Targeted Breast Milk Fortification for Very Low Birth Weight (VLBW) Infants: Nutritional Intake, Growth Outcome and Body Composition

Despite improvements in nutritional management, preterm infants continue to face high rates of postnatal growth restriction. Because variability in breast milk composition may result in protein and energy deficits, targeted fortification has been advocated. We conducted an interventional study to compare body composition and growth outcomes of very low birth weight infants fed targeted protein-fortified human milk (HM) with those fed standard fortified HM. If mother’s own milk was not available, donor milk was used. Weekly analysis of HM with mid-infrared spectroscopy was conducted and additional protein was added to the fortified HM to ensure a protein intake of 4 g/kg/day. Weekly anthropometric measurements were done. Prior to discharge or at 37 weeks, corrected age skinfold thickness (SFT) measurements as well as body composition measurement using air displacement plethysmography were done. Among 36 preterm infants enrolled, those in the targeted group (n = 17) received more protein and had a larger flank SFT at study end than those in the standard group (n = 19). A pilot post-hoc analysis of subjects having at least 30 intervention days showed a 3% higher fat-free mass in the targeted group. Use of a targeted fortification strategy resulted in a higher protein intake and fat-free mass among those receiving longer intervention.