Effects of quality of energy intake on growth and metabolic response of enterally fed low-birth-weight infants

Impact of Nutrient Intake on Body Composition in Very Low-Birth Weight Infants Following Early Progressive Enteral Feeding

Preterm infants have increased body adiposity at term-equivalent age and risk of adverse metabolic outcomes. The aim of the study was to define how nutrient intake may impact body composition (BC) of very low-birth weight infants fed with early progressive enteral feeding and standard fortification. Eighty-six infants with <1500 g birth weight were included in the BC study and stratified into extremely preterm (EP) and very preterm (VP) groups. Nutrient intake was calculated during the first 28 days and BC assessed by dual X-ray absorptiometry at discharge and by skinfold thickness at 12 months of corrected age (CA). Total nutrient intake did not differ between the groups. EP infants had a higher fat mass percentage at discharge than VP infants (24.8% vs. 19.4%, p < 0.001); lean mass did not differ. None of the nutrients had any impact on BC of EP infants. Protein intake did not result in a higher lean mass in either group; fat intake was a significant predictor of increased fat mass percentage in VP infants at discharge (p = 0.007) and body adiposity at 12 months of CA (p = 0.021). Nutritional needs may depend on gestational age and routine fortification should be used with caution in more mature infants.

Nutrient Composition of Donor Human Milk and Comparisons to Preterm Human Milk

BACKGROUND

Human milk is the preferred diet for very low birth weight (VLBW, <1500 g) infants. When mother's own milk is unable to meet the needs of VLBW infants, donor human milk (DHM) is the preferred alternative. Unfortunately, the composition of DHM remains elusive and no comparative studies between preterm human milk and DHM have been performed previously.

OBJECTIVES

We aimed to analyze the nutrient content of commercial pooled DHM and compare nutrient content in DHM with that of early and mature preterm human milk.

METHODS

We analyzed nutrient content in 15 DHM samples provided from 7 commercial milk banks including calories, carbohydrate, fat, protein, sodium, chloride, potassium, zinc, calcium, phosphorus, magnesium, and vitamin D and compared each nutrient to early (7 d of life) and mature (28 d of life) preterm human milk samples (n = 28-36 per nutrient, gestational age = 28 ± 3 wk). Protein-to-energy ratio and carbohydrate-to-nonprotein energy ratio were calculated for each sample and compared.

RESULTS

Mean values for all macro- and micronutrients in DHM are reported. In comparison to early or mature preterm human milk, DHM had significantly lower protein, sodium, chloride, potassium, and zinc content. Calorie, carbohydrate, calcium, phosphorus, magnesium, and vitamin D content did not differ statistically between DHM and early or mature preterm human milk. Fat content was modestly lower in early but not mature human milk when compared with DHM.

CONCLUSIONS

We provide mean values for several macro- and micronutrients for DHM and identify key differences between DHM and preterm human milk, which may be considered when designing human milk-based feeding plans. This study was registered at clinicaltrials.gov as NCT05742815.

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.

Early Energy Intake and Amino Acid Profile in Preterm Newborns: A Quasi-Experimental Study

(1) Background: An increased protein intake via parenteral nutrition (PN) in early life is associated with an improvement of the nitrogen balance in preterm newborns. However, the role of energy intake on amino acid (AA) utilization provided by PN remains to be defined. We investigated the effects of energy intake on blood AA levels and profiles. (2) Methods: Quasi-experimental study including preterm very low birth weight newborns who received an energy enhanced PN (Cohort A) or an energy standard PN (Cohort B), with a similar protein amount in the first week of life. Blood AA levels were measured between three and seven days of life (T0) and at fifteen days of life (T1) and compared between the two study cohorts. (3) Results: AA levels of 40 newborns from each group were analyzed. No difference was found for total essential and non-essential blood AA concentration at T0 between the two study cohorts. At T1, we found a significantly higher blood concentration of leucine, isoleucine and proline, and a significantly lower concentration of tyrosine in Cohort B. However, multivariate analysis did not confirm this result. (4) Conclusions: An enhanced PN protocol in terms of energy but not of protein did not influence AA levels and profiles. Considering the high risk of side effects, we suggest exercising caution when administering high energy intake via PN in the first week of life.

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.

The interaction between diet and neurobehavior in very low birth weight infants

BACKGROUND

Modulation of behavior and physiology by dietary perturbations early in life can provide clues to the pathogenesis of adult diseases. We tested the hypothesis that a period of early protein supplementation modulates sympathetic nervous system activity demonstrated indirectly by an increase in active sleep state distribution in very low birth weight (VLBW) infants.

METHODS

VLBW infants (n = 71) were randomized to a total parenteral nutritional regimen providing 18% of the energy intake as amino acids (AA) or a conventional regimen providing 12.5% to achieve targeted AA intakes of 4 g/kg/day (0.004 kcal/kg/day) and 3 g/kg/day (0.003 kcal/kg/day), respectively. Both groups were weaned to enteral feeding and advanced to provide similar AA intake of 4 g/kg/day (0.004 kcal/kg/day). Six-hour daytime, behavioral sleep studies were performed when the infants reached full enteral intake (165 ml/kg/day).

RESULTS

Infants in the high protein group spent more time in active sleep (77.2 ± 10.5% vs. 70.7 ± 11.8%), p < 0.01 and less time in quiet sleep (12.9 ± 3.4% vs. 17.7 ± 7.0%, p < 0.01) as compared to the conventional group. No group differences were observed for indeterminate sleep, awake, or crying states.

CONCLUSIONS

These results suggest that dietary intake may indirectly influence sympathetic nervous system activity.

IMPACT

Infants randomized to an early, high protein nutritional regimen spent an increased percentage of time in active sleep, supporting the hypothesis that nutrition and behavior are interactive. Furthermore, sleep states are an indirect measure of sympathetic nervous system activity, suggesting that dietary intake may influence sympathetic nervous system activity. This study highlights the importance of considering the impact of nutrition during critical periods of development in order to further understand and improve the long-term outcomes of very low birth weight infants.

Individualized Target Fortification of Breast Milk: Optimizing Macronutrient Content Using Different Fortifiers and Approaches

Background: Native breast milk composition displays significant inter- and intra-individual variation which persists after standard fortification with fixed doses and challenges target fortification. This study aims to analyze the macronutrient composition of different commercially available fortifiers and the effect of different fortification strategies on nutritional intake of preterm infants.

Methods: In 103 preterm infants, native breast milk samples were collected from 24-h feeding batches (n = 3,338) and fat, protein and carbohydrate contents were analyzed. Nutrient content was compared for breast milk that had undergone either (i) standard fortification, (ii) targeted fortification, (iii) selective batching according to breast milk composition, or (iv) partial lyophilization. For (i) eight commercially available standard fortifiers were tested. Targeted fortification (ii) involved the addition of single component modulars of either protein, fat or carbohydrates to standard fortified breast milk. Using a mathematical growth model, the combined effect of protein, fat and carbohydrate intake on growth was assessed. The best composition of standard fortifiers as the initial step for target fortification was explored assuming three clinical scenarios for milk analysis.

Results: Macronutrient content was highly variable between native breast milk samples, and this variation was still present after standard fortification, however at elevated macronutrient levels. Standard fortification, breast milk batching, as well as partial lyophilization of human milk resulted in deficient and imbalanced enteral intakes in a significant proportion of infants. Target fortification reduced this variation in a, respectively, higher percentage of samples. The effect size was dependent on the number of measurements per week. The optimum composition of standard fortifiers was dependent on the clinical scenario (measurement frequency) for target fortification.

Conclusions: To provide precise and accurate intakes of macronutrients, breast milk should be target fortified. Standard fortified breast milk can result in excess above recommended intakes of some macronutrients which limits the efficiency of target fortification. Standard fortifiers with improved composition are needed for target fortification.

Corrected fortification approach improves the protein and energy content of preterm human milk compared with standard fixed-dose fortification

OBJECTIVE

To evaluate whether a pragmatic corrected fortification (CF) model achieves recommended target protein and calorie content of human milk (HM) for preterm infants when compared with standard fixed-dose fortification (SF).

DESIGN

In this prospective non-interventional study, we enrolled mothers of infants with birth weight ≤1500 g fed exclusive HM. Infants with chromosomal or intestinal disorders were excluded. A total of 405 HM samples from 29 mothers and 45 donor milk samples were analysed for macronutrient content using a real-time HM analyser. A stepwise CF model was derived based on published data on HM calorie and protein content corrected for lactation stage and milk type. We applied both models to the measured protein and calorie content for all HM samples and compared the proportion of samples achieving target nutrient requirement in each group.

RESULTS

Target protein and calorie content of feed was achieved in 68% of HM samples with CF, compared with 5% samples with SF model (p<0.0001). For mother's own milk, none of the samples met the target macronutrient range with SF fortification during later lactation periods (≥week 5). With SF, over 40% of infants had poor growth (decline in weight z-score ≥0.8 SD) by 8 weeks. The final feed osmolality was acceptable for all fortification steps of the CF model.

CONCLUSION

The proposed CF model significantly improved the final protein and calorie content of HM with acceptable osmolality. It provides a proactive option to improve nutrient intake in premature infants.

Serial assessment of fat and fat-free mass accretion in very preterm infants: a randomized trial

BACKGROUND

Clinicians could modify dietary interventions during early infancy by monitoring fat and fat-free mass accretion in very preterm infants.

METHODS

Preterm infants were randomly assigned to either having reports on infant body composition available to the clinicians caring for them (intervention group) or not having reports available (control group). All infants underwent serial assessments of body composition by air-displacement plethysmography before 32 weeks of postmenstrual age (PMA) and at 36 weeks PMA. The primary outcome was percent body fat (%BF) at 3 months of corrected age (CA).

RESULTS

Fifty infants were randomized (median gestational age: 30 weeks; mean ± SD birth weight: 1387 ± 283 g). The mean %BF increased from 7 ± 4 before 32 weeks PMA to 20 ± 5 at 3 months CA. The differences in mean %BF between the intervention group and the control group were not statistically significant at 36 weeks PMA (14.5 vs. 13.6) or 3 months CA (20.8 vs. 19.4). Feeding practices and anthropometric measurements during hospitalization did not differ between groups.

CONCLUSIONS

Serial assessments of body composition in both intervention and control groups showed consistent increments in %BF. However, providing this information to clinicians did not influence nutritional practices or growth.

IMPACT

Serial assessments of body composition in preterm infants at 32 and 36 weeks postmenstrual age show consistent increments in % body fat up to 3 months of corrected age. However, providing this information to the clinician did not influence nutritional practices or growth.

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.

Milk analysis using milk analyzers in a standardized setting (MAMAS) study: A multicentre quality initiative

BACKGROUND

Human milk analyzers are increasingly used to rapidly measure the macronutrient content in breast milk for individual target fortification, to reduce the risk of postnatal growth restriction. However, many milk analyzers are used without calibration, validation or quality assurance.

AIMS

To investigate measurement quality between different human milk analyzers, to test whether accuracy and precision of devices can be improved by establishing individual calibration curves, and to assess long-term stability of measurements, following good clinical laboratory practice (GCLP).

METHODS

Sets of identical breast milk samples were sent to 13 participating centres in North America and Europe, for a total of 15 devices. The study included 3 sets of samples: A) initial assessment of the device's performance consisting of 10 calibration samples with random replicates; B) long term stability and quality control consisting of 2 batches of samples to be measured every time before the device is used, over 6 months; C) ring trial consisting of 2 samples to be measured monthly. The devices tested were Unity SpectraStar (n = 5) and MIRIS Human Milk Analyzer (n = 10).

RESULTS

There are significant variations in accuracy and precision between different milk analyzers' fat, protein and lactose measurements. However, the accuracy of measurements can be improved by establishing individual correction algorithms. Repeated measurements are more robust when coming from a larger batch volume. Long term stability also varies between devices.

CONCLUSION

The variations in measurements between devices are clinically significant and would impact both daily dietary prescriptions, and the outcomes of clinical studies assessing the effect of targeted adjustment of nutrient intake in preterm babies. This study shows that it is crucial to follow GCLP when using milk analyzers to ensure proper measurement of macronutrients, similar to what is required of other medical devices.

Protein use and weight-gain quality in very-low-birth-weight preterm infants fed human milk or formula

Background

Nutritional management of preterm infants aims to approximate the tissue growth and body composition of a fetus of the same postmenstrual age. The adequacy of the quality of protein supply can influence the rate and the relative quality of weight gain.

Objective

We investigated the protein balance according to feeding regimen and the association between human milk feeding and fat-free mass content at the term-corrected age in very-low-birth-weight preterm infants.

Design

A prospective observational study was conducted. Inclusion criteria were as follows: healthy infants, gestational age ≤32 wk, birth weight <1500 g, stable clinical conditions, and feeding by mouth with human milk or formula at discharge. Infants were enrolled at hospital discharge. At enrollment, macronutrient intakes and protein balance were determined. Anthropometric measurements and body composition were also assessed. The nutritional composition of human milk was calculated by infrared spectroscopy. The protein balance was determined according to the nitrogen balance standard method. Body composition was assessed by an air-displacement plethysmography system. At the term-corrected age, anthropometry and body composition assessments were repeated.

Results

Seventeen preterm infants fed fortified human milk and 15 preterm infants fed formula were enrolled. At discharge, despite similar macronutrient intakes, infants fed fortified human milk showed a higher nitrogen balance (expressed as mg · kg-1 · d-1) compared with preterm formula-fed infants (mean ± SD: 488.3 ± 75 compared with 409.8 ± 85 mg · kg-1 · d-1, P = 0.009). At term-corrected age, growth was similar in the 2 groups, whereas fortified human milk-fed infants showed a higher percentage of fat-free mass (85.1% ± 2.8% compared with 80.8% ± 3.2%, P = 0.002). Moreover, at multiple linear regression, fat-free mass content was independently associated with being fed human milk (R2 = 0.93, P < 0.0001).

Conclusion

Our findings suggest that human milk feeding is associated with early fat-free mass deposition in healthy and stable preterm infants. This trial was registered at www.clinicaltrials.gov as NCT03013374.

Nutritional intake and growth velocity in preterm extremely low-birthweight infants in Asia: Are we doing enough?

AIM

To describe nutritional practices among preterm extremely low-birthweight (ELBW) infants and their impact on growth and to compare differences in nutritional intervention and comorbidities between those with limited growth velocity (GV < 25th percentile) and those with GV > 25th percentile.

METHODS

A prospective cohort study was conducted to assess total protein and energy intake for week 1, days 14, 21 and 28 of life. Post-natal growth was calculated by measuring GV using an exponential model. Univariable analysis was applied to identify the potential risk factors associated with poor GV at day 28 and at discharge from hospital.

RESULTS

The median GV from birth to day 28 was 9.84 g/kg/day and 11.87 g/kg/day for GV from birth to discharge. Increased protein and energy intake was associated with higher GV at discharge. Hypotension needing inotropes, necrotising enterocolitis (NEC), patent ductus arteriosus and chronic lung disease were significantly associated with reduced GV at discharge. Infants with NEC, hypotension needing inotropes and sepsis took a significantly longer time to achieve full enteral nutrition. A longer time to attain full enteral feeds was associated with slower GV at discharge. Small-for-gestational-age babies increased from 22% at birth to 66.6% at discharge.

CONCLUSIONS

GV at discharge was positively correlated with increasing protein and energy intake in the first 28 days and adversely affected by the presence of neonatal morbidities. There was strong evidence of extra-uterine growth restriction, with the majority of preterm ELBW infants having lower z scores at discharge compared to at birth.

Nutritional support for low birth weight infants: insights from animal studies

Infants born with low birth weights (<2500 g, LBW), accounting for about 15 % of newborns, have a high risk for postnatal growth failure and developing the metabolic syndromes such as type 2 diabetes, CVD and obesity later in life. Improper nutrition provision during critical stages, such as undernutrition during the fetal period or overnutrition during the neonatal period, has been an important mediator of these metabolic diseases. Considering the specific physiological status of LBW infants, nutritional intervention and optimisation during early life merit further attention. In this review, the physiological and metabolic defects of LBW infants were summarised from a nutritional perspective. Available strategies for nutritional interventions and optimisation of LBW infants, including patterns of nutrition supply, macronutrient proportion, supplementation of amino acids and their derivatives, fatty acids, nucleotides, vitamins, minerals as well as hormone and microbiota manipulators, were reviewed with an aim to provide new insights into the advancements of formulas and human-milk fortifiers.

Length Normalized Indices for Fat Mass and Fat-Free Mass in Preterm and Term Infants during the First Six Months of Life

Objective: Postnatal tissue accretion in preterm infants differs from those in utero, affecting body composition (BC) and lifelong morbidity. Length normalized BC data allows infants with different body lengths to be compared and followed longitudinally. This study aims to analyze BC of preterm and term infants during the first six months of life. Methods: The BC data, measured using dual energy X-ray absorptiometry, of 389 preterm and 132 term infants from four longitudinal studies were combined. Fat-mass/length² (FMI) and fat-free mass/length² (FFMI) for postmenstrual age were calculated after reaching full enteral feeding, at term and two further time points up to six months corrected age. Results: Median FMI (preterm) increased from 0.4 kg/m² at 30 weeks to 2.5, 4.3, and 4.8 kg/m² compared to 1.7, 4.7, and 6 kg/m² in term infants at 40, 52, and 64 weeks, respectively. Median FFMI (preterm) increased from 8.5 kg/m² (30 weeks) to 11.4 kg/m² (45 weeks) and remained constant thereafter, whereas term FFMI remained constant at 11 kg/m² throughout the tested time points. Conclusion: The study provides a large dataset of length normalized BC indices. Followed longitudinally, term and preterm infants differ considerably during early infancy in the pattern of change in FMI and FFMI for age.

Comparing apples with apples: it is time for standardized reporting of neonatal nutrition and growth studies

The ultimate goal of neonatal nutrition care is optimal growth, neurodevelopment, and long-term health for preterm babies. International consensus is that increased energy and protein intakes in the neonatal period improve growth and neurodevelopment, but after more than 100 y of research the optimum intakes of energy and protein remain unknown. We suggest an important factor contributing to the lack of progress is the lack of a standardized approach to reporting nutritional intake data and growth in the neonatal literature. We reviewed randomized controlled trials and observational studies documented in MEDLINE and the Web of Science from 2008 to 2015 that compared approximately 3 vs. 4 g.kg(-1).d(-1) protein for preterm babies in the first month after birth. Consistency might be expected in the calculation of nutritional intake and assessment of growth outcomes in this relatively narrow scope of neonatal nutrition research. Twenty-two studies were reviewed. There was substantial variation in methods used to estimate and calculate nutritional intakes and in the approaches used in reporting these intakes and measures of infant growth. Such variability makes comparisons amongst studies difficult and meta-analysis unreliable. We propose the StRONNG Checklist-Standardized Reporting Of Neonatal Nutrition and Growth to address these issues.

Neonatal Body Composition: Measuring Lean Mass as a Tool to Guide Nutrition Management in the Neonate

Neonatal nutrition adequacy is often determined by infant weight gain. The aim of this review is to summarize what is currently known about neonatal body composition and the use of body composition as a measure for adequate neonatal nutrition. Unlike traditional anthropometric measures of height and weight, body composition measurements account for fat vs nonfat mass gains. This provides a more accurate picture of neonatal composition of weight gain. Providing adequate neonatal nutrition in the form of quantity and composition can be a challenge, especially when considering the delicate balance of providing adequate nutrition to preterm infants for catch-up growth. Monitoring weight gain as fat mass and nonfat mass while documenting dietary intake of fat, protein, and carbohydrate in formulas may help provide the medical community the tools to provide optimal nutrition for catch-up growth and for improved neurodevelopmental outcomes. Tracking body composition in term and preterm infants may also provide critical future information concerning the nutritional state of infants who go on to develop future disease such as obesity, hypertension, and hyperlipidemia as adolescents or adults.

Target fortification of breast milk: levels of fat, protein or lactose are not related

AIM

Target fortification (TFO) of breast milk has the potential to improve the nutritional outcomes of preterm infants. However, the primary logistic constraint in introducing TFO is analysers that rapidly and accurately analyse macronutrients (fat, protein and lactose). In this prospective observational study, we aim to evaluate whether the levels of fat, protein and carbohydrate could be predicted from one key macronutrient.

METHODS

Macronutrient components were measured in 543 breast milk samples using validated chemical micro-methods. Correlation analysis for fat versus protein, fat versus lactose and lactose versus protein was computed using Pearson's correlation.

RESULTS

The concentration of the macronutrients ranged from 0.7 to 10.3 g/100 mL (3.7 ± 1.2, mean ± SD) for fat, 0.7 to 3.2 g/100 mL (1.3 ± 0.3) for protein and 4.0 to 8.8 g/100 mL (5.8 ± 0.7) for lactose, respectively. There was no correlation between the three macronutrients.

CONCLUSION

This lack of correlation underlines the importance of routine and accurate analysis of all three macronutrients in breast milk prior to TFO.

Rapid measurement of macronutrients in breast milk: How reliable are infrared milk analyzers?

BACKGROUND & AIMS

Significant biological variation in macronutrient content of breast milk is an important barrier that needs to be overcome to meet nutritional needs of preterm infants. To analyze macronutrient content, commercial infrared milk analyzers have been proposed as efficient and practical tools in terms of efficiency and practicality. Since milk analyzers were originally developed for the dairy industry, they must be validated using a significant number of human milk samples that represent the broad range of variation in macronutrient content in preterm and term milk. Aim of this study was to validate two milk analyzers for breast milk analysis with reference methods and to determine an effective sample pretreatment. Current evidence for the influence of (i) aliquoting, (ii) storage time and (iii) temperature, and (iv) vessel wall adsorption on stability and availability of macronutrients in frozen breast milk is reviewed.

METHODS

Breast milk samples (n = 1188) were collected from 63 mothers of preterm and term infants. Milk analyzers: (A) Near-infrared milk analyzer (Unity SpectraStar, USA) and (B) Mid-infrared milk analyzer (Miris, Sweden) were compared to reference methods, e.g. ether extraction, elemental analysis, and UPLC-MS/MS for fat, protein, and lactose, respectively.

RESULTS

For fat analysis, (A) measured precisely but not accurately (y = 0.55x + 1.25, r(2) = 0.85), whereas (B) measured precisely and accurately (y = 0.93x + 0.18, r(2) = 0.86). For protein analysis, (A) was precise but not accurate (y = 0.55x + 0.54, r(2) = 0.67) while (B) was both precise and accurate (y = 0.78x + 0.05, r(2) = 0.73). For lactose analysis, both devices (A) and (B) showed two distinct concentration levels and measured therefore neither accurately nor precisely (y = 0.02x + 5.69, r(2) = 0.01 and y = -0.09x + 6.62, r(2) = 0.02 respectively). Macronutrient levels were unchanged in two independent samples of stored breast milk (-20 °C measured with IR; -80 °C measured with wet chemistry) over a period of 14 months.

CONCLUSIONS

Milk analyzers in the current configuration have the potential to be introduced in clinical routine to measure fat and protein content, but will need major adjustments.

Aggressive Nutrition of the Preterm Infant

Nutrition of preterm infants should result in growth similar to that of normally growing fetuses of the same gestational age. Unfortunately, most preterm infants are not fed enough to achieve this objective; as a result they are growth restricted by term gestation. Recent studies have demonstrated that early and enhanced "aggressive" nutrition of preterm infants can reduce postnatal growth failure and improve longer-term outcomes, particularly for the brain and its cognitive functions. When preterm infants are fed more aggressively (earlier onset of intravenous and enteral feeding, earlier achievement of full enteral feeding) cumulative energy and protein deficits are reduced and they consistently regain birth weight sooner, the incidence of necrotizing enterocolitis and late-onset sepsis is unchanged or reduced, and they achieve discharge criteria and go home sooner, with overall shorter hospital stays, and have improved anthropometrics by term gestation. More research is needed, however, to determine optimum feeding of preterm infants, particularly during periods of illness and physiological instability.

Target fortification of breast milk with fat, protein, and carbohydrates for preterm infants

OBJECTIVES

Fortification of breast milk is an accepted practice for feeding very low birth weight infants, however, fixed dosage enhancement does not address variations in native breast milk. This could lead to deficiencies in calories and macronutrients. We therefore established the infrastructure for target fortification in breast milk by measuring and adjusting fat, protein, and carbohydrate content daily. We analyzed nutrient intake, growth, and safety variables.

STUDY DESIGN

Each 12-hour batch of breast milk was analyzed using near-infrared spectroscopy. Macronutrients were individually added to routine fortification to achieve final contents for fat (4.4 g), protein (3 g), and carbohydrates (8.8 g) (per 100 mL). Fully breast milk fed healthy very low birth weight infants (<32 weeks) were fed the fortified breast milk for at least 3 weeks. Matched pair analysis of 20 infants fed routinely fortified breast milk was performed using birth weight, gestational age, and postnatal age.

RESULTS

All 650 pooled breast milk samples required at least 1 macronutrient adjusted. On average, 0.3 ± 0.4 g of fat, 0.7 ± 0.2 g of protein, and 1.2 ± 0.2 g of carbohydrate were added. Biochemistry was normal in the 10 target fortified infants (birth weight: 860 ± 309 g, 26.3 ± 1.6 weeks gestational age); weight gain was 19.9 ± 2.7 g/kg/d; and milk intake was 147 ± 5 mL/kg/d (131 ± 16 kcal/kg/d). Osmolality of fortified breast milk was 436 ± 13 mOsmol/kg. Matched pair analysis of infants indicated a higher milk intake (155 ± 5 mL/kg/d) but similar weight gain (19.7 ± 3.3 g/kg/d). No adverse event was observed. The linear relationship between milk intake and weight gain observed in study babies but not seen in matched controls may be related to the variable composition of breast milk.

CONCLUSIONS

Daily target fortification can be safely implemented in clinical routine and may improve growth.

The effects of varying protein and energy intakes on the growth and body composition of very low birth weight infants

Objective

To determine the effects of high dietary protein and energy intake on the growth and body composition of very low birth weight (VLBW) infants.

Study design

Thirty-eight VLBW infants whose weights were appropriate for their gestational ages were assessed for when they could tolerate oral intake for all their nutritional needs. Thirty-two infants were included in a longitudinal, randomized clinical trial over an approximate 28-day period. One control diet (standard preterm formula, group A, n = 8, 3.7 g/kg/d of protein and 129 kcal/kg/d) and two high-energy and high-protein diets (group B, n = 12, 4.2 g/kg/d and 150 kcal/kg/d; group C, n = 12, 4.7 g/kg/d and 150 kcal/kg/d) were compared. Differences among groups in anthropometry and body composition (measured with bioelectrical impedance analysis) were determined. An enriched breast milk group (n = 6) served as a descriptive reference group.

Results

Groups B and C displayed greater weight gains and higher increases in fat-free mass than group A.

Conclusion

An intake of 150 kcal/kg/d of energy and 4.2 g/kg/d of protein increases fat-free mass accretion in VLBW infants.

Early postnatal nutrition and programming of the preterm neonate

Early postnatal nutrition is a vital determinant of adult health; this is particularly true for the infant born prematurely and cared for in a hospital setting such as the neonatal intensive care unit. Human and animal studies support the contribution of postnatal dietary composition and the rate of extrauterine growth to long-term metabolic outcomes. One mechanism by which postnatal nutrition affects long-term outcome is via developmental programming. Programming, or the modulation of gene expression to impart a short-term advantage accompanied by a long-term cost, may be achieved by epigenetic modifications to chromatin. This review summarizes the details of postnatal nutritional content and rate of growth on the development of metabolic disease. The role of epigenetics in developmental programming of the preterm infant is also discussed, with an emphasis on animal models of dietary manipulation and directions in which the field must move in order to formulate effective feeding strategies for the preterm infant.

Graphical Exploration of Dimensions of Preterm Infant Growth in Weight in Association With Biological, Nutritional, and Energy Expenditure Conditions

The small sample sizes of studies involving preterm infants limit the use of statistics for examination of multivariate conditions contributing to clinically important growth dimensions of weight: rate of weight gain, body composition (fat-free and fat mass), and weight relative to reference infants (z score). The authors used graphical analyses, including multivariate proportional matrix, parallel coordinates, and bivariate plots with regression lines and splines, to explore specific variables derived from a theoretical model of biological, nutritional intake, and energy expenditure conditions influencing growth dimensions. The sample included 28 infants in 4 birth-weight categories: extremely low (<1,000 g), very low/smaller (1,000—1,249 g), very low/larger (1,250—1,499 g), and low (1,500—1,750 g). The authors examined the rate of weight gain before and after nipple feeding initiation. Fat-free mass was estimated with total body water and fetal reference data, and fat mass with skinfold thicknesses. Despite infants achieving the expected rate of weight gain for a fetus of the same postconceptional age, by hospital discharge 13 infants showed growth restriction with weight <10th centile. Infants with respiratory distress syndrome history were highest in negative z-score change from regain of birth weight to discharge, despite higher ordering on protein intake and fat-free mass. Graphical analyses provided visual patterns of distributions and orderings of measures of multiple variables that, taken together, identified potential influencing conditions and raised questions for further study. Other variables, including feeding protocols and practices, infant feeding competence, and health status, may contribute to variability in weight growth dimensions and influence relationships with biologic, nutritional, and energy expenditure conditions.

Docosahexaenoic Acid and Amino Acid Contents in Pasteurized Donor Milk are Low for Preterm Infants

OBJECTIVE

To evaluate whether pasteurized donor human milk meets the nutritional needs of preterm infants in terms of free fatty acid and amino acid contents.

STUDY DESIGN

Milk samples were prospectively collected from 39 donors to the Mothers' Milk Bank of Ohio. The fatty acid and amino acid compositions in donor milk samples were measured before and after pasteurization, and values were compared with previously published findings and preterm infant nutrition guidelines. The nutritional adequacy of donor milk for preterm infants was based on estimated daily intake of 150 mL/kg. Statistical significance was adjusted to account for multiple comparisons.

RESULTS

Pasteurization did not appreciably affect donor milk composition. Docosahexaenoic acid level (0.1 mol wt %), and concentrations of glycine, aspartate, valine, phenylalanine, proline, lysine, arginine, serine, and histidine in donor milk were all significantly lower than previously reported concentrations in milk.

CONCLUSIONS

Donor milk is not substantially affected by pasteurization, but has low concentrations of docosahexaenoic acid and amino acids. Targeted nutritional supplementation of human donor milk for feeding preterm infants might be warranted.

Nutritional support for extremely low-birth weight infants: abandoning catabolism in the neonatal intensive care unit

PURPOSE OF REVIEW

Obviously, the ultimate goal in neonatology is to achieve a functional outcome in premature infants that is comparable to healthy term-born infants. As nutrition is one of the key factors for normal cell growth, providing the right amount and quality of nutrients could prove pivotal for normal development. However, many premature infants are catabolic during the first week of life, which has directly been linked to growth failure, disease, and suboptimal long-term outcome. This review describes the progress in research on parenteral nutrition for premature infants with a focus on amino acids and the influence of nutrition on later outcome.

RECENT FINDINGS

Although randomized clinical trials on early nutrition for premature infants remain relatively sparse, evidence is accumulating on its beneficial effects both on the short-term and long-term. However, some research also warns for adverse effects.

SUMMARY

Despite the fact that substantially improved nutritional therapies for preterm neonates have been implemented, still, some reluctance exists when it comes to providing high amounts of nutrition to the most immature infants. Pros and cons are outlined, as well as deficits in knowledge, when it comes to providing the optimal nutrient strategy in the first postnatal phase.

Enteral nutrient supply for preterm infants: commentary from the European Society of Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition

The number of surviving children born prematurely has increased substantially during the last 2 decades. The major goal of enteral nutrient supply to these infants is to achieve growth similar to foetal growth coupled with satisfactory functional development. The accumulation of knowledge since the previous guideline on nutrition of preterm infants from the Committee on Nutrition of the European Society of Paediatric Gastroenterology and Nutrition in 1987 has made a new guideline necessary. Thus, an ad hoc expert panel was convened by the Committee on Nutrition of the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition in 2007 to make appropriate recommendations. The present guideline, of which the major recommendations are summarised here (for the full report, see http://links.lww.com/A1480), is consistent with, but not identical to, recent guidelines from the Life Sciences Research Office of the American Society for Nutritional Sciences published in 2002 and recommendations from the handbook Nutrition of the Preterm Infant. Scientific Basis and Practical Guidelines, 2nd ed, edited by Tsang et al, and published in 2005. The preferred food for premature infants is fortified human milk from the infant's own mother, or, alternatively, formula designed for premature infants. This guideline aims to provide proposed advisable ranges for nutrient intakes for stable-growing preterm infants up to a weight of approximately 1800 g, because most data are available for these infants. These recommendations are based on a considered review of available scientific reports on the subject, and on expert consensus for which the available scientific data are considered inadequate.

Effects of body position on thermal, cardiorespiratory and metabolic activity in low birth weight infants

BACKGROUND

Low birth weight (LBW) infants sleeping prone are known to exhibit many physiological differences from those sleeping supine, including lower energy expenditure (heat production) and higher surface temperature. This apparent increase in heat storage suggests that heat loss may be inhibited in the prone position which, in turn, might influence cardiorespiratory activity.

AIMS

To determine the effects of body position (prone vs. supine) on absolute surface temperature profile (heat storage), central-peripheral (C-P) thermal gradients (vasomotor response), cardiorespiratory activity and metabolic gas exchange in growing LBW infants.

METHODS

Six-hour continuous recordings of absolute surface temperature profiles, cardiorespiratory activity and O2 and CO2 exchange, along with minute-to-minute assessment of behavioral sleep states were performed in 32 healthy growing LBW infants (birth weight 805-1590 g, gestational age 26-35 weeks and postconceptional age at study 33-38 weeks). Each infant was randomly assigned to the prone or supine position for the first 3 h of the study and then reversed for the second 3 h. Surface temperatures were recorded from 4 sites (forehead, flank, forearm and leg) and averaged each minute. Central (forehead and flank)-to-peripheral (forearm and leg) and forehead-to-environment (H-E) thermal gradients were calculated from the surface temperatures. Corresponding sleep states were aligned with minute averages obtained from the temperature and cardiorespiratory measurements. Data were then sorted for prone and supine positions during quiet (QS) and active sleep (AS) and compared using paired t-tests.

RESULTS

In the prone position during both AS and QS, infants had higher forehead, flank, forearm and leg surface temperatures, narrower C-P gradients, higher heart rates and respiratory frequency, and lower heart rate and respiratory variability. Despite similar environmental temperatures, the H-E gradient was higher in the prone position. In the prone position infants demonstrated lower O2 consumption and CO2 production and a higher respiratory quotient.

CONCLUSIONS

Despite thermoregulatory adjustments in cardiorespiratory function, infants sleeping prone have relatively higher body temperature. The cardiorespiratory responses to this modest increase in temperature indicate that thermal and metabolic control of cardiac and respiratory pumps seem to work in opposition. The consequences of any attendant changes in blood gas activity (e.g. hypocapnia and/or increased mixed venous oxygen concentration) due to this override of metabolic control remains speculative.

Bedside analysis of human milk for adjustable nutrition strategy

AIM

Mother's milk is optimum for preterm infants, but human milk fortifier is required at times, because some nutrients are sometimes insufficient for infant growth. It is important to measure the nutrients in breast milk at bedside so that the amount of nutrients that need to be supplemented can be determined. A human milk analyser (HMA, Miris) is currently available. We examined if the macronutrient values measured by human milk analyser are comparable with those measured by conventional methods. We also sought to discover whether we could dilute the milk sample used for the human milk analyser measurement if the amount of milk available for testing was insufficient.

SUBJECTS AND METHODS

First, the results of protein, fat and lactose content in breast milk samples obtained using the human milk analyser and conventional methods were compared. Second, we measured diluted samples and compared the values with nondiluted samples.

RESULTS

When comparing the human milk analyser and conventional methods, all three nutrients exhibited a significantly positive correlation (p < 0.001); lactose content was reliable on the condition that it is 6-7 g/dL. The lactose content measured by the HPLC method was obtained by 3.05 x human milk analyser value - 13.4. When comparing diluted and nondiluted samples, fat and protein had expected values after dilution whereas lactose did not.

CONCLUSION

The human milk analyser can inform us about the amount of major nutrients in breast milk: fat, protein and lactose. However, when human milk is diluted, the lactose content measured by the human milk analyser is overestimated.

Probiotics and prebiotics in inflammatory bowel disease: microflora 'on the scope'

The intestinal microflora is a large bacterial community that colonizes the gut, with a metabolic activity equal to an organ and various functions that affect the physiology and pathology of the host's mucosal immune system. Intestinal bacteria are useful in promotion of human health, but certain components of microflora, in genetically susceptible individuals, contribute to various pathological disorders, including inflammatory bowel disease. Clinical and experimental observations indicate an imbalance in protective and harmful microflora components in these disorders. Manipulation of gut flora to enhance its protective and beneficial role represents a promising field of new therapeutic strategies of inflammatory bowel disease. In this review, we discuss the implication of gut flora in the intestinal inflammation that justifies the role of probiotics and prebiotics in the prevention and treatment of inflammatory bowel disease and we address the evidence for therapeutic benefits from their use in experimental models of colitis and clinical trials.

Optimal protein and energy intakes in preterm infants

There is compelling evidence that current nutritional practice fails to provide sufficient dietary protein for preterm infants, especially extremely and very low birth weight infants. Nutrient requirements can be estimated by a variety of techniques, but most suggest that these infants will require a protein intake of 3.5-4.0 g/kg/d. Even when these infants are able to tolerate full enteral feeds, most currently available artificial milk formula or breast milk fortifiers will not ensure these protein requirements are met except when fed at high volumes. Energy requirements on the other hand may be currently met, and evidence from controlled studies suggests that intakes higher than 110-135 kcal/kg/d might not be beneficial. The data from studies on neonatal adiposity outcomes, and from studies examining relationship between early growth and later cardiovascular outcome, also suggest that excess nutrient intake might be harmful. In the light of this data, optimal intakes and protein-energy ratios require re-appraisal.

Use of Lactobacillus casei subspecies Rhamnosus GG and gastrointestinal colonization by Candida species in preterm neonates

Candida species increasingly cause morbidity and mortality in the premature infant in neonatal intensive care units, and the gut reservoir is the site from which dissemination most frequently starts in such patients. Specific antifungal prophylaxis is the most suitable strategy with which to limit the severity and the frequent neurodevelopmental impairment in survivors that is associated with neonatal invasive fungal infections. Recent interest has focused on the use of probiotics for the treatment of several diseases in neonatal patients. Pilot studies have implicated these organisms in necrotizing enterocolitis, sepsis, and urinary tract infections. Other applications of probiotic therapy in preterm neonates may also include the prevention of fungal colonization and of Candida-related disorders. Probiotics could provide an innovative and less invasive approach because they modify the bowel flora by colonizing the gastrointestinal tract. Basic research has shown that in mice models, the Lactobacillus casei subsp Rhamnosus GG (LGG) is effective in preventing Candida gut colonization and systemic dissemination. A pilot, randomized, double-blind, placebo-controlled trial in human preterm neonates has demonstrated that LGG administered in the first month of life significantly reduces enteric Candida colonization. The present article summarizes the state of the art about probiotics and Candida-related diseases in the preterm neonate and emphasizes the need for further investigations to determine unequivocally the possible role of LGG in the prevention and management of the fungal diseases in preterm neonates.

Evaluation of postnatal weight growth in very low birth weight infants

There is general agreement about the need for longitudinal studies of very low birth weight infants (VLBWI) to evaluate their postnatal growth and to generate distance and velocity charts that allow neonatologists and pediatricians to detect earlier whether a child is not growing adequately. There are no satisfactory growth charts for VLBWI. We analyzed the weight growth of 262 VLBWIs from birth to 2 years of corrected age. Individual growth profiles were fitted with a 7-constant exponential-logistic function suitable for modelling weight growth pattern. After a postnatal weight loss, all VLBWIs showed a late neonatal peak of velocity between the seventh and 21st weeks; the large majority of them also experienced an early neonatal peak between the second and the sixth weeks. Small-for-gestational-age VLBWIs with major morbidities grew less than reference appropriate-for-gestational-age VLBWIs without major morbidities: at 2 years, the difference in weight was about 860 g. The more severe growth impairment in VLBWIs with major morbidities was almost entirely due to the reduced height of the late neonatal peak of velocity. The mathematical function used in this study is expected to be a useful tool to trace model-based longitudinal distance and velocity charts specific for VLBWIs. Moreover, this function also could be used to evaluate to what extent different pathological conditions or nutritional and medical care protocols affect growth kinetics.

Enteral intake for very low birth weight infants: what should the composition be?

Providing optimal nutrition to satisfy the growth needs of very low birth weight infants is critical. The available preterm formulas and fortified human milk diets provide protein intakes of approximately 3.5 to 3.6 g/kg/d when volumes sufficient to provide 120 kcal/kg/d are fed to these infants. These intakes support growth and protein accretion at about or slightly greater than intrauterine rate and lead to relatively increased fat deposition. However, most very low birth infants fed these diets remain below the 10th percentile of the intrauterine growth standards at discharge. There is clear evidence that, with respect to growth, very low birth infants are likely to benefit from a higher protein intake; however, there is no clear evidence that energy intakes greater than 120 kcal/kg/d are needed. Although the upper limit of protein intake and the ideal protein:energy ratio remain controversial, there is enough evidence to support the beneficial and safe use of formulas providing protein:energy ratio of 3.2 to 3.3 g/100 kcal.

Osmolality of preterm formulas supplemented with nonprotein energy supplements

BACKGROUND

Addition of energy supplements to preterm formulas is an optional strategy to increase the energy intake in infants requiring fluid restriction, in conditions like bronchopulmonary dysplasia. This strategy may lead to an undesirable increase in osmolality of feeds, the maximum recommended safe limit being 400 mOsm/kg. The aim of the study was to measure the changes in osmolality of several commercialized preterm formulas after addition of glucose polymers and medium-chain triglycerides.

METHODS

Osmolality was measured by the freezing point depression method. Six powdered formulas with concentrations of 14 g/100 ml and 16 g/100 ml, and five ready-to-feed liquid formulas were analyzed. All formulas, were supplemented with 10% (low supplementation) or 20% (high supplementation) of additional calories, respectively, in the form of glucose polymers and medium chain triglycerides, maintaining a 1:1 glucose:lipid calorie ratio. Inter-analysis and intra-analysis coefficients of variation of the measurements were always < 3.9%.

RESULTS

The mean osmolality (mOsm/kg) of the non-supplemented formulas varied between 268.5 and 315.3 mOsm/kg, increasing by 3-5% in low supplemented formulas, and by 6-10% in high supplemented formulas. None of the formulas analyzed exceeded 352.8 mOsm/kg.

CONCLUSION

The supplementation of preterm formulas with nonprotein energy supplements with up to 20% additional calories did not exceed the maximum recommended osmolality for neonatal feedings.

Parenteral amino acid and energy administration to premature infants in early life

After birth, the nutritional supply through the umbilical cord ceases. Premature infants do not immediately tolerate full enteral feedings, yet they retain high nutritional needs for both growth and metabolic maintenance. Parenteral nutrition should therefore be initiated as quickly as possible after premature birth, thereby reducing the dependence on endogenous substrates. Intrauterine studies show very high amino acid uptake, clearly exceeding accretion rates. Studies covering the early neonatal period demonstrate that the initiation of high-dose amino acid administration directly after birth is safe and effective, even at low energy intakes. Future research should reveal whether usage could be improved through better amino acid solutions or by providing more energy via lipids from birth onwards as well.

Nutritional support in the premature newborn

The theory and practice of nutritional support in the premature newborn has assumed increasing importance with survival of greater numbers of very immature infants. After birth, many do not tolerate full enteral feeding until gastrointestinal motor function has matured. During this process some will develop necrotising enterocolitis (NEC), a devastating failure of adaptation to postnatal life that may result in death, or severe complications. The feeding strategy that minimises the risk of NEC remains to be defined. In addition, promoting growth rates and nutrient accretion equivalent to those achieved during fetal development while optimising neurodevelopmental and long term health outcomes represents an important challenge for neonatologists. This review will focus on the problems associated with enteral nutrition, the requirement for parenteral nutrition, and the long term consequences of early nutritional interventions, underlining the need for prolonged follow up in assessing the potential benefits of different approaches to feeding.

Postnatal growth, neurodevelopment and altered adiposity after preterm birth--from a clinical nutrition perspective

Evidence reveals a dilemma that under-nutrition and growth retardation during brain growth are associated with neurodevelopmental deficits, and nutritional supplement resulting in catch-up growth and relative visceral adiposity leads to metabolic/cardiovascular morbidities. Hyperinsulinaemia secondary to insulin resistance appears to play a central role in the development of visceral adiposity through its action on adipocyte beta3-adrenoceptor.

CONCLUSION

Optimal nutritional management to minimize hyperinsulinaemia and insulin resistance may potentially improve neurodevelopment and facilitate catch-up growth with normal body composition.

Increased energy intake for preterm infants with (or developing) bronchopulmonary dysplasia/ chronic lung disease

BACKGROUND

Preterm infants with bronchopulmonary dysplasia/chronic lung disease have nutritional deficits that may contribute to short and long term morbidity and mortality. Increasing the daily energy intake for these infants may improve their respiratory, growth and neurodevelopmental outcomes.

OBJECTIVES

To assess the effect of increased energy intake on mortality and respiratory, growth and neurodevelopmental outcomes for preterm infants with (or developing) CLD/BPD. Secondarily, the review examines any adverse effects associated with increased energy intake.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006) , MEDLINE (accessed via Ovid), references cited in previous relevant Cochrane reviews and in other relevant studies, review articles, standard textbooks, and manuals of neonatal medicine. Hand search results of the Cochrane Neonatal Review Group were also assessed.

SELECTION CRITERIA

All randomized and quasi-randomized trials comparing the outcomes of preterm infants with (or developing) CLD/BPD who had either increased (> 135 kcal/kg/day) or standard energy intake (98 to 135 kcal/kg/day). Increasing energy intake might be achieved enterally and/or parenterally, enterally by increasing the energy content of the milk, increasing feed volume, or by nutrient supplementation with protein, carbohydrate or fat. The primary outcomes were the development of CLD and neonatal mortality; secondary outcomes included respiratory morbidities, growth, neurodevelopmental status and possible complications with increased energy intake.

DATA COLLECTION AND ANALYSIS

We planned to extract data using the standard methods of the Cochrane Neonatal Review Group. Relevant trials would be scrutinized for methodological quality independently by the reviewers to determine their eligibility for inclusion. Data of the included trials would be expressed as relative risk, risk difference, NNT and weighted mean difference where appropriate, using a fixed effect model.

MAIN RESULTS

No eligible trials were identified. Twelve studies that appeared to be relevant were excluded, as no study directly compared increased versus standard energy intakes in infants with CLD/BPD. However, two excluded trials provided some insights into the topic. One study showed that infants with CLD/BPD who were fed formula enriched with protein and minerals had improved growth parameters up until the cessation of the intervention at three months of corrected age. The other study compared different energy density of formula but identical energy intake by setting different feed volumes for both groups. It showed that both groups were unable to achieve the pre-designated feed volumes, and that there were no differences in growth, respiratory outcomes, oedema and the diuretic requirements.

AUTHORS' CONCLUSIONS

To date, no randomized controlled trials are available that examine the effects of increased versus standard energy intake for preterm infants with (or developing) CLD/BPD. Research should be directed at evaluating the effects of various levels of energy intake on this group of infants on clinically important outcomes like mortality, respiratory status, growth and neurodevelopment. The benefits and harms of various ways of increasing energy intake, including higher energy density of milk feed and/or fluid volume (clinically realistic target volume should be set), parenteral nutrition, and the use of various constituents of energy like carbohydrate, protein and fat for this purpose also need to be assessed.

Feeding preterm infants after hospital discharge: a commentary by the ESPGHAN Committee on Nutrition

Survival of small premature infants has markedly improved during the last few decades. These infants are discharged from hospital care with body weight below the usual birth weight of healthy term infants. Early nutrition support of preterm infants influences long-term health outcomes. Therefore, the ESPGHAN Committee on Nutrition has reviewed available evidence on feeding preterm infants after hospital discharge. Close monitoring of growth during hospital stay and after discharge is recommended to enable the provision of adequate nutrition support. Measurements of length and head circumference, in addition to weight, must be used to identify those preterm infants with poor growth that may need additional nutrition support. Infants with an appropriate weight for postconceptional age at discharge should be breast-fed when possible. When formula-fed, such infants should be fed regular infant formula with provision of long-chain polyunsaturated fatty acids. Infants discharged with a subnormal weight for postconceptional age are at increased risk of long-term growth failure, and the human milk they consume should be supplemented, for example, with a human milk fortifier to provide an adequate nutrient supply. If formula-fed, such infants should receive special postdischarge formula with high contents of protein, minerals and trace elements as well as an long-chain polyunsaturated fatty acid supply, at least until a postconceptional age of 40 weeks, but possibly until about 52 weeks postconceptional age. Continued growth monitoring is required to adapt feeding choices to the needs of individual infants and to avoid underfeeding or overfeeding.

Early provision of parenteral amino acids in extremely low birth weight infants: relation to growth and neurodevelopmental outcome

OBJECTIVE

To determine if postnatal growth failure exerts an adverse effect on subsequent growth and neurodevelopment.

STUDY DESIGN

A secondary analysis of 1018 infants who were enrolled in a randomized, clinical trial of glutamine supplementation was performed to determine whether early provision of parenteral amino acids (AA) is associated with better growth and neurodevelopmental outcomes. Infants were stratified by whether they were provided > or =3 g/kg per day of AA at < or =5 days of life (early; n = 182) or not (late; n = 836).

RESULTS

At 36 weeks' postmenstrual age, significant differences were found in weight, length, and head circumference in favor of the infants who received early AA; the odds of having weight less than the 10(th) percentile for age was 4-fold higher for infants in the late group. At 18 months' CA, there were no differences in weight, length, or measures of neurodevelopment between the groups; however, male infants in the late group were twice as likely to have head circumference less than the 10(th) percentile.

CONCLUSIONS

Early AA were associated with significantly better growth outcomes at 36 weeks' postmenstrual age, and fewer infants who received early AA were found to have suboptimal head growth at 18 months' CA.

Protein requirements in preterm infants: effect of different levels of protein intake on growth and body composition

This study compares growth and body composition in preterm infants (< or =1750 g birth weight, < or =34 wk gestation) fed three iso-caloric formulas (80 kcal/100 mL) with different protein concentrations (A = 3.3 g/100 kcal, B = 3.0 g/100 kcal, C = 2.7 g/100 kcal). The study began when full enteral feeding (150 mL/kg/d) was established and lasted until term plus 12 wk corrected age (T + 12 wca). Nutrient intake was closely monitored throughout the study; daily during initial hospital stay and following discharge averaged between each clinic visit. Anthropometry and serum biochemistries were determined weekly during initial stay and at each clinic visit. Body composition was measured after hospital discharge and at T + 12 wca. Seventy-seven infants were recruited. No differences were detected in birth/enrollment characteristics between the groups. Protein intake was closely paralleled by changes in serum urea nitrogen and differed between the groups. Infants in group A were heavier and longer and had greater head circumference at discharge, but this was confounded by a slightly older corrected age in this group. There were no significant anthropometric differences at term or T + 12 wca. No differences were detected in body composition between the groups following discharge or at T + 12 wca. An intake of 3.3 g/100 kcal appears safe and may promote increased growth before initial hospital discharge. After discharge, intakes greater than 2.7 g/100 kcal do not appear to offer clear advantage. Further studies are needed to more precisely define protein requirements in these nutritionally at-risk infants.

Considerations and approaches in determining the protein and energy composition of preterm infant formulas

Optimal early nutritional support is considered a crucial issue in the care of the preterm infant, particularly of those with very low- or extremely low-brithweight. Unfortunately, this goal is seldom satisfactorily attained. Several conditions such as hypoxia, acidosis, patent ductus arteriosus, drug therapy, reduced intestinal motility may interfere with an adequate nutritional delivery in the early neonatal period. Moreover, there is still concern about metabolic and intestinal tolerance of the currently suggested intakes and a lack of uniformity in the nutritional program among different NICUs. Finally, the vast majority of the available preterm formulas are not fully adequate to the real nutritional needs of these infants. Inadequate protein content and inappropriate protein energy ratio of most preterm formulas represent a matter of major concern, since there is a strict relationship between formula composition and the quantity and quality of weight gain. As a consequence there is a need of at least two milk formulas for different preterm infants: one for LBW and VLBW infants, the other for preterm infants weighing >1500 g.

The developing intestinal ecosystem: implications for the neonate

Interactions of resident intestinal microbes with the luminal contents and the mucosal surface play important roles in normal intestinal development, nutrition, and innate and adaptive immunity. The neonate, especially the premature, who possesses a highly immunoreactive intestinal submucosa underlying a single layer of epithelial cells that are continuously exposed to the luminal environment, is highly susceptible to perturbations of the luminal environment. Understanding the interactions of the intestinal ecosystem with the host and luminal nutritional environment, especially in regard to human milk and pre- and probiotics, has major implications for the pathogenesis of diseases that affect not only the intestine but distal organs such as the lung and brain.