Improved growth of very low birthweight infants

Postdischarge Nutrition in Preterm Infants

The field of postdischarge nutrition for preterm infants arose when concerns that using diets suitable for term infants-breastfeeding without fortification or standard formulas-might not meet the postdischarge nutritional needs of infants born preterm, who often exhibited growth restriction and evidence of undernutrition. A decade ago, there were already 27 randomized controlled trials (RCTs) of nutritional supplementation from which an eligible subsample of trials have provided evidence on whether nutritional fortification of human milk or nutrient-enriched formula favorably affects postdischarge growth in these infants. These RCTs also allowed exploration of the quality of growth, bone mineralization, and the ad libitum-fed infant's own regulation of milk volume and nutrient intake. Importantly, such RCTs, augmented by observational data on the links between growth and neurodevelopment, have allowed exploration of the potential impact of postdischarge nutrition on neurocognitive function. However, the interpretation of published data and the implication for practice has proven difficult and contentious. In this review, we examine, and to an extent reanalyze, existing evidence to elucidate its strengths and limitations, with the goal of adding more clarity to the ways in which this sizeable body of clinical scientific research may have a positive impact on the postdischarge nutritional approach to infants born preterm.

Impact of macronutrient supplements on later growth of children born preterm or small for gestational age: A systematic review and meta-analysis of randomised and quasirandomised controlled trials

BACKGROUND

Nutritional supplements may improve short-term growth of infants born small (preterm or small for gestational age), but there are few data on long-term effects and concerns that body composition may be adversely affected. Effects also may differ between girls and boys. Our systematic review and meta-analysis assessed the effects of macronutrient supplements for infants born small on later growth.

METHODS AND FINDINGS

We searched OvidMedline, Embase, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews from inception to January 30, 2020, and controlled-trials.com, clinicaltrials.gov, and anzctr.org.au on January 30, 2020. Randomised or quasirandomised trials were included if the intention was to increase macronutrient intake to improve growth or development of infants born small and growth was assessed after discharge. Primary outcome was body mass index (BMI) in childhood. Data were pooled using random-effect models. Outcomes were evaluated in toddlers (< 3 years), childhood (3 to 8 years), adolescence (9 to 18 years), and adulthood (>18 years). Forty randomised and 2 quasirandomised trials of variable methodological quality with 4,352 infants were included. Supplementation did not alter BMI in childhood (7 trials, 1,136 children; mean difference [MD] -0.10 kg/m2, [95% confidence interval (CI) -0.37 to 0.16], p = 0.45). In toddlers, supplementation increased weight (31 trials, 2,924 toddlers; MD 0.16 kg, [0.01 to 0.30], p = 0.03) and length/height (30 trials, 2,889 toddlers; MD 0.44 cm, [0.10 to 0.77], p = 0.01), but not head circumference (29 trials, 2,797 toddlers; MD 0.15 cm, [-0.03 to 0.33], p = 0.10). In childhood, there were no significant differences between groups in height (7 trials, 1,136 children; MD 0.22 cm, [-0.48 to 0.92], p = 0.54) or lean mass (3 trials, 354 children; MD -0.07 kg, [-0.98 to 0.85], p = 0.88), although supplemented children appeared to have higher fat mass (2 trials, 201 children; MD 0.79 kg, [0.19 to 1.38], p = 0.01). In adolescence, there were no significant differences between groups in BMI (2 trials, 216 adolescents; MD -0.48 kg/m2, [-2.05 to 1.08], p = 0.60), height (2 trials, 216 adolescents; MD -0.55 cm, [-2.95 to 1.86], p = 0.65), or fat mass (2 trials, 216 adolescents; MD -1.3 5 kg, [-5.76 to 3.06], p = 0.55). In adulthood, there also were no significant differences between groups in weight z-score (2 trials, 199 adults; MD -0.11, [-0.72 to 0.50], p = 0.73) and height z-score (2 trials, 199 adults; MD -0.07, [-0.36 to 0.22], p = 0.62). In subgroup analysis, supplementation was associated with increased length/height in toddler boys (2 trials, 173 boys; MD 1.66 cm, [0.75 to 2.58], p = 0.0003), but not girls (2 trials, 159 girls; MD 0.15 cm, [-0.71 to 1.01], p = 0.74). Limitations include considerable unexplained heterogeneity, low to very low quality of evidence, and possible bias due to low or unbalanced followup.

CONCLUSIONS

In this systematic review and meta-analysis, we found no evidence that early macronutrient supplementation for infants born small altered BMI in childhood. Although supplements appeared to increase weight and length in toddlers, effects were inconsistent and unlikely to be clinically significant. Limited data suggested that supplementation increased fat mass in childhood, but these effects did not persist in later life. PROSPERO registration: CRD42019126918.

Impact of macronutrient supplements for children born preterm or small for gestational age on developmental and metabolic outcomes: A systematic review and meta-analysis

BACKGROUND

Nutritional supplements may improve development of infants born small (preterm or small for gestational age [SGA]) but may increase the risk of later metabolic disease. We conducted a systematic review and meta-analysis to assess the effects of macronutrient supplements for infants born small on later development and metabolism.

METHODS AND FINDINGS

We searched OvidMedline, Embase, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews from inception to April 1, 2019, and controlled-trials.com, clinicaltrials.gov, and anzctr.org.au. Randomised or quasirandomised trials were included if the intention was to increase macronutrient intake to improve growth or development of infants born small and assessed post-discharge outcomes. Co-primary outcomes were cognitive impairment and metabolic risk, evaluated in toddlers (<3 years), childhood (3 to 8 years), and adolescence (9 to 18 years). Two reviewers independently extracted data. Quality was assessed using the Cochrane Risk of Bias tool, and data were pooled using random-effect models. Twenty-one randomised and one quasirandomised trial of variable methodological quality involving 3,680 infants were included. In toddlers born small, supplementation did not alter cognitive impairment (relative risk [RR] 1.00; 95% confidence interval [CI] 0.67 to 1.49; P = 0.99), and there were no differences in cognitive scores (mean difference [MD] 0.57; 95% CI -0.71 to 1.84; P = 0.38) or motor scores (MD 1.16; 95% CI -0.32 to 2.65; P = 0.12) between supplemented and unsupplemented groups. However, fewer supplemented children had motor impairment (RR 0.76; 95% CI 0.62 to 0.94; P = 0.01). In subgroup analyses, supplementation improved cognitive scores in boys (MD 5.60; 95% CI 1.07 to 10.14; P = 0.02), but not girls born small (MD -2.04; 95% CI -7.04 to 2.95; P = 0.42), and did not alter cognitive or motor scores in the subgroup of children born SGA. In childhood, there was no difference in cognitive impairment (RR 0.81; 95% CI 0.26 to 2.57; P = 0.72) or cognitive scores (MD 1.02; 95% CI -1.91 to 3.95; P = 0.50) between supplemented and unsupplemented groups. There were also no differences in blood pressure, triglyceride, and low-density lipoprotein (LDL) concentrations (all P > 0.05). However, supplemented children had lower fasting glucose (mmol/L: MD -0.20; 95% CI -0.34 to -0.06; P = 0.005) and higher high-density lipoprotein (HDL) concentrations (mmol/L: MD 0.11; 95% CI 0.02 to 0.19; P = 0.02). In subgroup analyses, there was no evidence of differences in blood pressure between supplemented and unsupplemented groups in boys or girls born small, or in SGA children. In adolescence, there was no difference between supplemented and unsupplemented groups in blood pressure, triglycerides, LDL and HDL concentrations, fasting blood glucose, insulin resistance, and fasting insulin concentrations (all P > 0.05). Limitations include considerable unexplained heterogeneity, low to very low quality of the evidence, and limited data beyond early childhood.

CONCLUSIONS

In this systematic review and meta-analysis of randomised trials, we found no evidence that early macronutrient supplementation for infants born small altered later cognitive function, although there was some evidence that supplementation may decrease motor impairment in toddlers. Contrary to the findings from observational studies, evidence from randomised trials suggests that early macronutrient supplementation for infants born small improves some metabolic outcomes in childhood.

PROSPERO REGISTRATION

CRD42019127858.

Nutrient-enriched formula versus standard formula for preterm infants following hospital discharge

BACKGROUND

Preterm infants are often growth-restricted at hospital discharge. Feeding nutrient-enriched formula rather than standard formula to infants after hospital discharge might facilitate 'catch-up' growth and might improve development.

OBJECTIVES

To compare the effects of nutrient-enriched formula versus standard formula on growth and development of preterm infants after hospital discharge.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (2016, Issue 8) in the Cochrane Library, MEDLINE, Embase and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; to 8 September 2016), as well as conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the effects of feeding nutrient-enriched formula (postdischarge formula or preterm formula) versus standard term formula to preterm infants after hospital discharge .

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and extracted data independently. We analysed treatment effects as described in the individual trials and reported risk ratios and risk differences for dichotomous data, and mean differences (MDs) for continuous data, with respective 95% confidence intervals (CIs). We used a fixed-effect model in meta-analyses and explored potential causes of heterogeneity by performing sensitivity analyses. We assessed quality of evidence at the outcome level using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 16 eligible trials with a total of 1251 infant participants. Trials were of variable methodological quality, with lack of allocation concealment and incomplete follow-up identified as major potential sources of bias. Trials (N = 11) that compared feeding infants with 'postdischarge formula' (energy density about 74 kcal/100 mL) versus standard term formula (about 67 kcal/100 mL) did not find consistent evidence of effects on growth parameters up to 12 to 18 months post term. GRADE assessments indicated that evidence was of moderate quality, and that inconsistency within pooled estimates was the main quality issue.Trials (N = 5) that compared feeding with 'preterm formula' (about 80 kcal/100 mL) versus term formula found evidence of higher rates of growth throughout infancy (weighted mean differences at 12 to 18 months post term: about 500 g in weight, 5 to 10 mm in length, 5 mm in head circumference). GRADE assessments indicated that evidence was of moderate quality, and that imprecision of estimates was the main quality issue.Few trials assessed neurodevelopmental outcomes, and these trials did not detect differences in developmental indices at 18 months post term. Data on growth or development through later childhood have not been provided.

AUTHORS' CONCLUSIONS

Recommendations to prescribe 'postdischarge formula' for preterm infants after hospital discharge are not supported by available evidence. Limited evidence suggests that feeding 'preterm formula' (which is generally available only for in-hospital use) to preterm infants after hospital discharge may increase growth rates up to 18 months post term.

Post-discharge formula feeding in preterm infants: A systematic review mapping evidence about the role of macronutrient enrichment

BACKGROUND & AIMS

Preterm infants are a heterogeneous group and many accumulate growth deficits before and after initial hospital discharge. Although this is associated with worse cognitive outcome, recent meta-analyses suggest that nutrient fortification of breast milk, or the use of nutrient and energy rich formulae after discharge exert little effect on growth and neurodevelopment. However, the complexity of study design, inclusion criteria and outcome parameters, combined with differences in formula composition mean that meta-analysis may overlook important effects of differing interventions in sub-groups.

METHODS

We systematically identified evidence and mapped the information on Participants, Intervention, Comparator, and Outcome (PICO) from 31 published studies illustrating the marked heterogeneity in study design and interventions next to outcomes on (quality of) growth and neurodevelopment.

RESULTS

Despite significant heterogeneity in study design, we found that nutrient enriched diets after discharge show no negative effects but frequently improve growth parameters at some point in the course of the study, in particular for boys. The data indicates that when energy requirements are adequate, increased protein results in increased growth and lean mass (LM) accretion; In particular, higher protein to energy ratios lead to increased lean mass accretion, and increased head circumference (HC) at one year. However, improvements in neurodevelopmental outcome were rarely seen.

CONCLUSION

This comprehensive evidence mapping approach to the field provides a broad but detailed overview of the currently available evidence. Furthermore, we identified key gaps in existing knowledge on the role of nutrient enrichment in the post-discharge period.

Nutrient-enriched formula versus standard term formula for preterm infants following hospital discharge

BACKGROUND

Preterm infants are often growth-restricted at hospital discharge. Feeding infants after hospital discharge with nutrient-enriched formula rather than standard term formula might facilitate "catch-up" growth and improve development.

OBJECTIVES

To determine the effect of feeding nutrient-enriched formula compared with standard term formula on growth and development for preterm infants following hospital discharge.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2011, Issue 4), MEDLINE, EMBASE, and CINAHL (to September 2011), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared the effect of feeding preterm infants following hospital discharge with nutrient-enriched formula (post-discharge formula or preterm formula) compared with standard term formula.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors.

MAIN RESULTS

We found 15 eligible trials in which a total of 1128 preterm infants participated. The trials were of variable methodological quality with lack of allocation concealment and incomplete follow-up in some trials being the major potential sources of bias. The trials (N = 10) that compared feeding infants with "post-discharge formula" (energy density about 74 kcal/100 ml) versus standard term formula (about 67 kcal/100 ml) did not find consistent evidence of effects on growth parameters up to 12 to 18 months corrected age. The trials (N = 5) that compared feeding with "preterm formula" (about 80 kcal/100 ml) versus term formula found some evidence of higher rates of growth through infancy: weighted mean differences at 12 to 18 months corrected age about 500 g in weight, 5 to10 mm in length, and 5 mm in head circumference. Few trials assessed neurodevelopmental outcomes and these did not detect any statistically significant differences in developmental indices at 18 months corrected age. There are not yet any data on growth or development through later childhood.

AUTHORS' CONCLUSIONS

Current recommendations to prescribe "post-discharge formula" for preterm infants following hospital discharge are not supported by the available evidence. Some limited evidence exists that feeding preterm infants following hospital discharge with "preterm formula" (which is generally only available for in-hospital use) may increase growth rates up to 18 months corrected age.

Continuing care of NICU graduates

After a prolonged and complicated hospital stay, the NICU graduate enters the world with unique and complex medical problems. A well-coordinated multidisciplinary approach is essential in the follow-up care of these infants. The crucial issues for the pediatrician who cares for these infants are assisting in the catch-up growth and the ongoing healing process with good nutritional supplementation, while preventing further problems by detecting and treating illness early. Timely inclusion of other appropriate health care personnel and facilities in the care may be crucial and rewarding. The role of the pediatrician in helping these infants attain their full physical, neurodevelopmental, emotional, and psychosocial potential by providing optimal care is invaluable. With appropriate support most NICU graduates will become productive and well-adjusted adults. The pediatrician plays a major role in completing this process and contributes to the eventual success of the neonatal intensive care that these infants are subjected to at the very beginning of their lives.

The effects of the introduction of a high-nutrient transitional formula on growth and development of very-low-birth-weight infants

OBJECTIVE

The purpose of this study was to determine the impact of introducing a high-nutrient transitional formula (TF) for use after discharge on the growth and development of premature infants.

STUDY DESIGN AND METHODS

This was a cohort study of all surviving infants with a birth weight < or =1250 g admitted to the neonatal intensive care unit between January 1, 1995 and December 31, 1996. Infants with major congenital abnormalities were excluded. There were 180 infants discharged, including 66 on TF and 114 on standard formulas for full-term infants.

RESULTS

Use of TF started the week before discharge, and increased from 10% in 1995 to 66% in 1996 (p<0.001). Regression analyses controlling for multiple confounders identified TF as a significant contributor to improved weight at 3 months and length at 18 months. Bayley developmental scores were not affected.

CONCLUSION

Introduction of a TF for very-low-birth-weight infants resulted in improved growth after discharge.

Growth of preterm infants fed nutrient-enriched or term formula after hospital discharge

OBJECTIVE

At hospital discharge, preterm infants may have low body stores of nutrients, deficient bone mineralization, and an accumulated energy deficit. This double-blind, randomized study evaluated the growth of premature infants with birth weights <1800 g who were fed a 22 kcal/fl oz nutrient-enriched postdischarge formula (PDF) or a 20 kcal/fl oz term-infant formula (TF) from hospital discharge to 12 months' corrected age (CA).

METHODS

Infants were randomized to PDF or TF a few days before hospital discharge with stratification by gender and birth weight (<1250 g or >/=1250 g). The formulas were fed to 12 months' CA. Growth was evaluated using analysis of variance controlling for site, feeding, gender, and birth weight group. Interaction effects were also assessed. Secondary analyses included a repeated measures analysis and growth modeling.

RESULTS

One hundred twenty-five infants were randomized; 74 completed to 6 months' CA and 53 to 12 months' CA. PDF-fed infants weighed more than TF-fed infants at 1 and 2 months' CA, gained more weight from study day 1 to 1 and 2 months' CA, and were longer at 3 months' CA. There were significant interactions between feeding and birth weight group-among infants with birth weights <1250 g, those fed PDF weighed more at 6 months' CA, were longer at 6 months' CA, had larger head circumferences at term 1, 3, 6, and 12 months' CA, and gained more in head circumference from study day 1 to term and to 1 month CA. The repeated measures and growth modeling analyses confirmed the analysis of variance results. The PDF formula seemed to be of particular benefit for the growth of male infants. Infants fed the PDF consumed less formula and had higher protein intakes at several time points. Energy intakes, however, were not different.

CONCLUSIONS

Growth was improved in preterm infants fed a nutrient-enriched postdischarge formula after hospital discharge to 12 months' CA. Beneficial effects were most evident among infants with birth weights <1250 g, particularly for head circumference measurements.

Enhanced-calorie formulas: considerations and options

The long-term developmental impact of nutrition on the preterm newborn has recently been shown to be of even greater importance than previously recognized. Very immature or ill infants are challenged by the need for a high caloric intake, but are unable to tolerate large fluid volumes. These patients may require enhanced-calorie formulas to achieve the desired growth goals. Formula enhancement has traditionally been performed by uniquely developed recipes of base formula concentration with the addition of powdered formula or single components such as medium-chain triglycerides oil, protein, or polycose. These mixtures have been largely unstudied for bioavailability, long-term outcomes, and tolerance. Deviation from recommended protein, fat, carbohydrate, mineral, and vitamin delivery limits may impair growth or lead to undesirable side effects. The practitioner must have an understanding of when and how to use an enhanced formula and the important monitoring and assessment needs of the patient receiving enhanced-calorie formula.

Postnatal attainment of intrauterine macromineral accretion rates in low birth weight infants fed fortified human milk

HYPOTHESIS

Provision of more bioavailable mineral sources as human milk supplements enables very low birth weight (VLBW) infants to meet the intrauterine accretion rate for calcium and phosphorus.

DESIGN

Comparison of currently formulated human milk fortifier with previous formulation.

SETTING

Neonatal level II and III nurseries.

PATIENTS

Twenty-six healthy, VLBW infants, whose mothers chose to breast-feed.

INTERVENTIONS

We tested the effects of two formulations designed for VLBW infants as human milk supplements and differing primarily in their quantity and source of Ca, P, and magnesium. The study interval began with a milk intake of 100 ml.kg-1.day-1 and ended when a body weight reached 2.0 kg.

MAIN OUTCOME MEASURES

Net absorption and retention of Ca, P, and Mg during a nutritional balance study conducted once during the study interval, growth during the entire study interval, and bone mineral content of the radius were measured at the beginning and end of the study interval.

RESULTS

The newer Ca gluconate-glycerophosphate preparation (given to group CaGP) resulted in greater net absorption and retention of Ca and P (p < 0.01) than in infants given Ca phosphate (group CaTB). Mg retention was greater than (in group CaGP) or equivalent to (in group CaTB) the intrauterine accretion rate. Radius bone mineral content was significantly greater in group CaGP than in group CaTB (p < 0.001). Volumes of the fortified human milk preparation needed to meet the needs for gain in body weight were higher in group CaGP than in group CaTB (p < 0.001).

CONCLUSIONS

Intrauterine accretion rates for Ca and P can be achieved when VLBW infants are fed human milk supplemented with Ca gluconate-glycerophosphate. Supplementation of human milk with Mg may not be indicated. In this study, greater intakes of Ca and P, and not improvements in bioavailability, result in improved net retention and bone mineral content of VLBW infants.