Early Amino Acids in Extremely Preterm Infants and Neurodisability at 2 Years

Effects of Early Enteral to Parenteral Protein Ratios on Brain Volume and Somatic Growth in Very Low Birth Weight Infants

OBJECTIVE

To evaluate whether a higher proportion of enteral vs parenteral protein ratio (E:P ratio) in the first 28 days after birth is associated with increased brain volume and somatic growth in very low birth weight (VLBW; birth weight <1500 g) infants.

STUDY DESIGN

This was a retrospective analysis of a subcohort of VLBW infants (n = 256, gestational age mean 28.07 [SD 2.17] weeks, birth weight 1038.80 [SD 262.95] grams) from the Cincinnati Infant Neurodevelopment Early Prediction Study, a regional prospective study of infants born at ≤32 weeks' gestation. Brain magnetic resonance imaging was obtained at term-equivalent age. Macronutrient intake and growth metrics for the first 28 days were collected retrospectively. The primary outcome was total brain tissue volume. The relationships between E:P ratio, total and regional brain tissue volumes, and somatic growth were analyzed by multivariable linear regression models; composite variables were used to adjust for potential confounders including pregnancy risk factors and initial severity of illness.

RESULTS

Higher E:P ratio was associated with increased total brain tissue volume but was not associated with change in head circumference z score. In secondary analyses, higher E:P ratio was associated with increased weight velocity. There were no significant associations between E:P ratio and change in weight or length z scores or regional brain volumes.

CONCLUSIONS

Higher E:P ratio in the first 28 days was positively associated with total brain volume and weight gain. Promoting the provision of enteral over parenteral protein may improve brain and somatic growth in VLBW infants.

[Interpretation of the 2023 "Guidelines for parenteral nutrition in preterm infants: the American Society for Parenteral and Enteral Nutrition"]

The "Guidelines for parenteral nutrition in preterm infants: the American Society for parenteral and enteral nutrition" were developed by the American Society for Parenteral and Enteral Nutrition and published in the Journal of Parenteral and Enteral Nutrition in September 2023. The guidelines provide recommendations on 12 key clinical questions regarding parenteral nutrition (PN) for preterm infants. In comparison to similar guidelines, this set offers more detailed perspectives on PN for preterm infants. It presents evidence-based recommendations for the commencement time, nutrient dosage, and composition of PN, considering primary outcomes such as growth and development, as well as secondary outcomes like sepsis, retinopathy of prematurity, parenteral nutrition-related liver disease, and jaundice. This article aims to interpret the guidelines to provide a reference for colleagues in the field.

Early hypophosphataemia and refeeding syndrome in extremely low birthweight babies and outcomes to 2 years of age: secondary cohort analysis from the ProVIDe trial

OBJECTIVE

To investigate in extremely low birthweight (ELBW; <1000 g) babies the associations between refeeding syndrome (serum phosphate <1.4 mmol·L-1 and serum total calcium>2.8 mmol·L-1) and hypophosphataemia in the first week and death or neurodisability at 2 years' corrected age (CA).

DESIGN

Secondary cohort analysis of the ProVIDe trial participants with serum biochemistry within 7 days of birth. At 2 years' CA, neurodisability was assessed by Bayley Scales of Infant Development Edition III and neurological examination. Associations between neurodisability and other variables were analysed using t-tests and logistic regression adjusted for sex and smallness-for-gestational age.

SETTING

Six tertiary neonatal intensive care units (NICUs) in New Zealand.

PARTICIPANTS

352 ELBW babies born between 29 April 2014 and 30 October 2018.

MAIN OUTCOME MEASURE

Death or neurodisability at 2 years' CA.

RESULTS

Fifty-nine babies died, two after discharge from the NICU. Of the 336 babies who survived to 2 years' CA, 277 had neurodevelopmental assessment and 107 (39%) had a neurodisability. Death or neurodisability was more likely in babies who had refeeding syndrome (aOR 1.96 (95% CI 1.09 to 3.53), p=0.02) and in babies who had hypophosphataemia (aOR 1.74 (95% CI 1.09 to 2.79), p=0.02). Hypophosphataemia was associated with increased risk of death (aOR 2.07 (95% CI 1.09 to 3.95), p=0.03)) and severe hypophosphataemia (<0.9 mmol·L-1) with increased risk of death (aOR 2.67 (95% CI 1.41 to 5.00), p=0.002) and neurodisability (aOR 2.31 (95% CI 1.22 to 4.35), p=0.01).

CONCLUSIONS

In ELBW babies, refeeding syndrome and hypophosphataemia in the first week are associated with death or neurodisability. Until optimal phosphate requirements are determined through further research, monitoring for hypophosphataemia and mitigation strategies are indicated.

TRIAL REGISTRATION NUMBER

ACTRN12612001084875.

Postnatal growth and neurodevelopment at 2 years' corrected age in extremely low birthweight infants

BACKGROUND

Faltering postnatal growth in preterm babies is associated with adverse neurodevelopment. However, which growth reference is most helpful for predicting neurodevelopment is unknown. We examined associations between faltering growth and developmental delay in extremely low birthweight (ELBW) infants.

METHODS

We categorized faltering growth (z-score decrease ≥0.8 for weight/length, >1 for head circumference) between birth, 4 weeks, 36 weeks' postmenstrual age and 2 years' corrected age using fetal (Fenton, UK-WHO and Olsen) and healthy preterm (INTERGROWTH-21st) references. Associations between faltering growth and developmental delay were examined using binary logistic regression and area under the receiver operating curve (AUC).

RESULTS

In 327 infants, Olsen charts identified the highest prevalence of faltering growth (weight 37%, length 63%, head 45%). Agreement in classification was higher amongst fetal references (kappa coefficient, ĸ = 0.46-0.94) than between INTERGROWTH-21st and fetal references (ĸ = 0.10-0.81). Faltering growth in all measures between 4-36 weeks (odds ratio, OR 2.0-4.7) compared with other time intervals (OR 1.7-2.7) were more strongly associated with developmental delay, particularly motor delay (OR 2.0-4.7). All growth references were poorly predictive of developmental delay at 2 years (AUC ≤ 0.62).

CONCLUSIONS

Faltering postnatal growth in ELBW infants is associated with, but is poorly predictive of, developmental delay at 2 years.

IMPACT

In babies born preterm, different growth references result in wide variation in categorization of faltering postnatal growth. Faltering growth in weight, length, and head circumference from 4 weeks to 36 weeks' postmenstrual age are associated with developmental delay at 2 years' corrected age, particularly motor delay. However, postnatal growth is a poor predictor of later developmental delay in extremely low birthweight infants irrespective of the growth reference used.

An exploratory study of clinical factors associated with IGF-1 and IGFBP-3 in preterm infants

BACKGROUND

Despite advances in parenteral nutrition, postnatal growth failure in very low birthweight (VLBW) preterm infants is common and associated with chronic health problems. Insulin-like growth factor 1 (IGF-1) is positively associated with improved infant growth, but factors which promote IGF-1 levels in this population have not been clearly identified. The objective of this study was to explore early factors that influence IGF-1 in VLBW preterm infants.

METHODS

VLBW infants were enrolled into a prospective, randomized controlled nutrition trial (N = 87). Outcome measures included IGF-1 and IGFBP-3 levels measured at 35 weeks PMA. Linear regression analyses tested the relationships between candidate clinical predictors and levels of IGF-1 and IGFBP-3.

RESULTS

Higher protein intake, longer duration of parenteral nutrition, and lower IGFBP-3 levels at 1 week of life were associated with lower IGF-1 levels at 35 weeks PMA. Neither early markers of insulin resistance nor degree of illness were associated with IGF-1 levels at 35 weeks PMA.

CONCLUSION

Optimization of early nutrient intake, and attention to route of delivery, may have a lasting influence on IGF-1/IGFBP-3, and in turn, long-term health outcomes.

IMPACT

In very low birthweight preterm infants, early protein intake, duration of parenteral nutrition, and insulin-like growth factor binding protein 3 (IGFBP-3) levels at 1 week of life are positively associated with insulin-like growth factor 1 (IGF-1) levels at 35 weeks postmenstrual age. Data from this study highlight the influence of early nutrition on components of the endocrine axis in preterm infants. Strategies aimed at early initiation of enteral nutrition, as well as optimizing composition of parenteral nutrition, may bolster hormones involved in promoting preterm infant growth.

High protein intake on later outcomes in preterm children: a systematic review and meta-analysis

BACKGROUND

Appropriate protein intake is crucial for growth and development in children born preterm. We assessed the effects of high (HP) versus low protein (LP) intake on neurodevelopment, growth, and biochemical anomalies in these children.

METHODS

Randomised and quasi-randomised trials providing protein to children born preterm (<37 completed weeks of gestation) were searched following PRISMA guideline in three databases and four registers (PROSPERO registration CRD42022325659). Random-effects model was used for assessing the effects of HP (≥3.5 g/kg/d) vs. LP (<3.5 g/kg/d).

RESULTS

Data from forty-four studies (n = 5338) showed HP might slightly reduce the chance of survival without neurodisability at ≥12 months (four studies, 1109 children, relative risk [RR] 0.95 [95% CI 0.90, 1.01]; P = 0.13; low certainty evidence) and might increase risk of cognitive impairment at toddler age (two studies; 436 children; RR 1.36 [0.89, 2.09]; P = 0.16; low certainty evidence). At discharge or 36 weeks, HP intake might result in higher weight and greater head circumference z-scores. HP intake probably increased the risk of hypophosphatemia, hypercalcemia, refeeding syndrome and high blood urea, but reduced risk of hyperglycaemia.

CONCLUSIONS

HP intake for children born preterm may be harmful for neonatal metabolism and later neurodisability and has few short-term benefits for growth.

IMPACT STATEMENT

Planned high protein intake after birth for infants born preterm might be harmful for survival, neurodisability and metabolism during infancy and did not improve growth after the neonatal period. Protein intake ≥3.5 g/kg/d should not be recommended for children born preterm.

Dynamic impact of delivery modes on gut microbiota in preterm infants hospitalized during the initial 4 weeks of life

Preterm infants face a high risk of various complications, and their gut microbiota plays a pivotal role in health. Delivery modes have been reported to affect the development of gut microbiota in term infants, but its impact on preterm infants remains unclear. Here, we collected fecal samples from 30 preterm infants at five-time points within the first four weeks of life. Employing 16 S rRNA sequencing, principal coordinates analysis, the analysis of similarities, and the Wilcoxon rank-sum test, we examined the top dominant phyla and genera, the temporal changes in specific taxa abundance, and their relationship with delivery modes, such as Escherichia-Shigella and Enterococcus based on vaginal delivery and Pluralibacter related to cesarean section. Moreover, we identified particular bacteria, such as Taonella, Patulibacter, and others, whose proportions fluctuated among preterm infants born via different delivery modes at varying time points, as well as the microbiota types and functions. These results indicated the influence of delivery mode on the composition and function of the preterm infant gut microbiota. Importantly, these effects are time-dependent during the early stages of life. These insights shed light on the pivotal role of delivery mode in shaping the gut microbiota of preterm infants and have significant clinical implications for their care and management.

Early versus late parenteral nutrition in term and late preterm infants: a randomised controlled trial

BACKGROUND

There is limited evidence regarding the optimal time to commence parenteral nutrition (PN) in term and late preterm infants.

DESIGN

Single-centre, non-blinded, exploratory randomised controlled trial.

SETTING

A level-3 neonatal unit in a stand-alone paediatric hospital.

PATIENTS

Infants born ≥34 weeks of gestation and ≤28 days, who needed PN. Eligible infants were randomised on day 1 or day 2 of admission.

INTERVENTIONS

Early (day 1 or day 2 of admission, N=30) or late (day 6 of admission, N=30) PN.

MAIN OUTCOME MEASURES

Plasma phenylalanine and F2-isoprostane levels on day 4 and day 8 of admission. Secondary outcomes were amino-acid and fatty-acid profiles on day 4 and day 8, and clinical outcomes.

RESULTS

The postnatal age at randomisation was similar between the groups (2.3 (SD 0.8) vs 2.3 (0.7) days, p=0.90). On day 4, phenylalanine levels in early-PN infants were higher than in late-PN (mean (SD) 62.9 (26.7) vs 45.5 (15.3) µmol/L; baseline-adjusted percentage difference 25.8% (95% CI 11.6% to 39.9%), p<0.001). There was no significant difference in phenylalanine levels between the two groups on day 8. There was no significant difference between the groups for F2-isoprostane levels on day 4 (early-PN mean (SD) 389 (176) vs late-PN 419 (291) pg/mL; baseline-adjusted percentage difference: -4.4% (95% CI -21.5% to 12.8%) p=0.62) and day 8 (mean (SD) 305 (125) vs 354 (113) pg/mL; adjusted mean percentage difference -16.1 (95% CI -34.1 to 1.9) p=0.09).Postnatal growth restriction for weight was less severe in the early-PN group (change in weight z-score from baseline to discharge: -0.6 (0.6) vs -1.0 (0.6); p=0.02). The incidence of hyperglycaemia was greater in the early-PN group (20/30 (66.7%) vs 11/30 (36.7%), p=0.02).

CONCLUSIONS

The timing of the commencement of PN did not seem to affect the degree of oxidative stress in critically ill term and late preterm infants. The effect of transiently high plasma phenylalanine with early PN on clinical outcomes requires further investigation.

TRIAL REGISTRATION NUMBER

ACTRN12620000324910.

Targeting optimal protein delivery in parenteral and enteral nutrition for preterm infants: a review of randomized, controlled trials

Close attention to nutritional management is essential for optimizing growth and neurodevelopment of the preterm infant. Protein intake and the protein to energy ratio are the main determinants of growth and body composition. Yet large, multi-center, randomized controlled trials are lacking to guide protein delivery for the preterm infant. Until these studies are pursued, smaller trials must be used to inform clinical practice. This review summarizes the randomized controlled trials that have been performed to test the impact of higher vs. lower protein delivery to the preterm infant. We consider the trials that varied protein delivery rates during parenteral and enteral phases of nutrition. Considerable heterogeneity exists across study designs. Still, cumulative evidence from these trials provides a framework for current recommendations for protein intake in the preterm infant.

Outcomes following the adoption of standard parenteral nutrition in preterm infants: a whole-population non-concurrent control study

OBJECTIVE

To evaluate the impact of a quality improvement project of the adoption of standard parenteral nutrition (SPN) in preterm infants.

DESIGN

Retrospective, multicentre, whole-population, non-concurrent control study using data from the UK National Neonatal Research Database between 1 January 2014 and 31 December 2020.

SETTING

Neonatal units in London UK organised by geographical network.

PATIENTS

Preterm infants <31 weeks' gestation.

INTERVENTIONS

Introduction of two SPN formulations previously tested in randomised controlled trials (NEON and SCAMP). SCAMP delivers a higher target macronutrient intake.

MAIN OUTCOME MEASURES

The primary outcome was survival to discharge from neonatal care without major morbidities. Secondary outcomes included the individual components of the primary outcome and a comparison of outcomes between the NEON and the SCAMP formulations.

RESULTS

Of 6538 eligible infants, 4693 were admitted to neonatal care before and 1845 after the adoption of SPN. Morbidity-free survival decreased by an average of 8.6% (95% CI 5.8% to 11.4%, p<0.0001) following adoption. The effect varied by type of formulation; the cohort that adopted NEON showed no difference in morbidity-free survival, whereas the cohort that adopted SCAMP showed a statistically significant decrease in morbidity-free survival. Overall survival decreased by an average of 2.0% (95% CI 0.01% to 4.0%, p=0.048).

CONCLUSIONS

Research is urgently needed to identify the optimal composition of parenteral nutrition for preterm babies. This study also adds to the growing body of evidence that suggests that early and high intakes of macronutrients in preterm babies may be harmful.

Associations between neonatal nutrition and visual outcomes in 7-year-old children born very preterm

PURPOSE

There is uncertainty about the effect of increased neonatal protein intake on neurodevelopmental outcomes following preterm birth. The aim of this study was to assess the effect of a change in neonatal nutrition protocol at a major tertiary neonatal intensive care unit intended to increase protein intake on ophthalmic and visual development in school-age children born very preterm.

METHODS

The study cohort comprised children (n = 128) with birthweight <1500 g or gestational age < 30 weeks born at Auckland City Hospital before (OldPro group, n = 55) and after (NewPro group, n = 73) a reformulation of parenteral nutrition that resulted in increased total protein intake during the first postnatal week and decreased carbohydrate, total parenteral fluid and sodium intake. Clinical and psychophysical vision assessments were completed at 7 years' corrected age, including visual acuity, global motion perception (a measure of dorsal stream function), stereoacuity, ocular motility and ocular health. Composite measures of favourable overall visual, binocular and functional visual outcomes along with individual vision measures were compared between the groups using logistic and linear regression models.

RESULTS

Favourable overall visual outcome did not differ between the two groups. However, global motion perception was better in the NewPro group (p = 0.04), whereas the OldPro group were more likely to have favourable binocular visual outcomes (60% vs. 36%, p = 0.02) and passing stereoacuity (p = 0.02).

CONCLUSIONS

These results indicate subtle but complex associations between early neonatal nutrition after very preterm birth and visual development at school age.

Neurodevelopmental Outcome in Very Preterm Infants Randomised to Receive Two Different Standardised, Concentrated Parenteral Nutrition Regimens

We have previously shown that increasing parenteral protein (target: 3.8 versus 2.8 g/kg/d) and energy (12% versus 10% glucose; 3.8 versus 2.8 g/kg/d) intake using a Standardised, Concentrated with Added Macronutrients Parenteral (SCAMP) nutrition regimen ameliorates early head growth failure in very-preterm infants (VPIs). We hypothesised that the SCAMP nutrition regimen would also improve neurodevelopmental outcome. The original double-blind randomised, controlled study (ISRCTN: 76597892) received ethical approval. VPIs were randomised to either start SCAMP or remain on the control regimen. The consent process included neurodevelopmental assessments (Bayley III), all of which were performed (blinded) at 2-3.5 years of corrected gestational age. Bayley III assessments were performed for 38/60 SCAMP survivors and 41/63 control survivors at means of (sd) 29.2 (3.7) and 20.0 (3.9) months, respectively. Motor, cognitive, language, and combined scores were all higher in the SCAMP intervention group, but none of the differences were statistically significant. Nutrient intake and biochemical monitoring data confirmed that protein/energy ratios were maintained in the SCAMP intervention group without increasing the incidence of hyperglycaemia, insulin treatment, or the derangement of plasma mineral/electrolyte levels. This study did not show a statistically significant improvement in neurodevelopmental outcome when administering higher parenteral protein/energy intakes despite optimal energy and mineral intakes.

Nutrition-based implications and therapeutics in the development and recovery of bronchopulmonary dysplasia

Premature births account for over 10% of live births worldwide. Bronchopulmonary dysplasia (BPD) represents a severe sequela in neonates born very prematurely and remains the most common chronic neonatal lung disease, often leading to serious adverse consequences in adulthood. Nutrition plays a crucial role in lung development and repair. Ongoing research has primarily focused on the pathogenesis and prevention of BPD in preterm birth. However, infants with established BPD need specialist medical care that persists throughout their hospitalization and continues after discharge. This manuscript aims to highlight the impact of growth and nutrition on BPD and highlight research gaps to provide direction for future studies. Protective practices include ensuring adequate early energy delivery through parenteral nutrition and enteral feedings while carefully monitoring total fluid intake and the use of breast milk over formula. These nutritional strategies remain the same for infants with established BPD with the addition of limiting the use of diuretics and steroids; but if employed, monitoring carefully without compromising total energy delivery. Functional nutrient supplements with a potential protective role against BPD are revisited, despite the limited evidence of their efficacy, including vitamins, trace elements, zinc, lipids, and sphingolipids. Planning post-intensive care and outpatient longitudinal nutrition support is critical in caring for an infant with established BPD.

Significant Published Articles in 2022 for Pharmacy Nutrition Support Practice

Purpose: The purpose of this article is to assist the pharmacist engaged in nutrition support therapy in staying current with pertinent literature. Methods: Several clinical pharmacists engaged in nutrition support therapy compiled a list of articles published in 2022 considered important to their clinical practice. The citation list was compiled into a spreadsheet where the author participants were asked to assess whether the article was considered important to nutrition support pharmacy practice. A culled list of publications was then identified whereby at least 5 out of the 8 author participants considered the article to be important. Guideline and consensus papers, important to practice but not ranked, were also included. Results: A total of 162 articles were identified; 8 from the primary literature were voted by the group to be of high importance. An additional 10 guidelines, position, recommendation, or consensus papers were also identified. The top-ranked articles from the primary literature were summarized and a narrative regarding its implications to pharmacy nutrition support practice were provided. Conclusion: We recommend that pharmacists engaged in nutrition support therapy be familiar with these articles as it pertains to their practice.

Early Human Milk Fortification in Infants Born Extremely Preterm: A Randomized Trial

OBJECTIVES

Enteral nutrition with unfortified human milk during the first 2 postnatal weeks often leads to cumulative protein and energy deficits among preterm infants. Fortified human milk administered soon after birth could increase fat-free mass (FFM) and improve growth in these infants.

METHODS

This was a masked, randomized trial. Starting on feeding day 2, extremely preterm infants 28 weeks or younger fed maternal or donor milk were randomized to receive either a diet fortified with a human-based product (intervention group) or a standard, unfortified diet (control group). This practice continued until the feeding day when a standard bovine-based fortifier was ordered. Caregivers were masked. The primary outcome was FFM-for-age z score at 36 weeks of postmenstrual age (PMA).

RESULTS

A total of 150 infants were randomized between 2020 and 2022. The mean birth weight was 795±250 g, and the median gestational age was 26 weeks. Eleven infants died during the observation period. The primary outcome was assessed in 105 infants (70%). FFM-for-age z scores did not differ between groups. Length gain velocities from birth to 36 weeks PMA were higher in the intervention group. Declines in head circumference-for-age z score from birth to 36 weeks' PMA were less pronounced in the intervention group.

CONCLUSIONS

In infants born extremely preterm, human milk diets fortified soon after birth do not increase FFM accretion at 36 weeks' PMA, but they may increase length gain velocity and reduce declines in head circumference-for-age z scores from birth to 36 weeks' PMA.

Administering Parenteral Nutrition in the Neonatal Intensive Care Unit: Logistics, Existing Challenges, and a Few Conundrums

Use of parenteral nutrition (PN) in the neonatal intensive care unit (NICU) requires evaluating the need for central venous catheters, potential drug incompatibilities, unintentional exposures, and suboptimal energy and nutrient intake during the transition to full enteral nutrition. Risks of photooxidation reactions in PN components, refeeding syndrome, and excess early amino acid intake should prompt the reevaluation of routine practices. The goal of this paper is to review the practicalities, challenges, and conundrums of administering PN in the NICU.

Guidelines for parenteral nutrition in preterm infants: The American Society for Parenteral and Enteral Nutrition

BACKGROUND

Parenteral nutrition (PN) is prescribed for preterm infants until nutrition needs are met via the enteral route, but unanswered questions remain regarding PN best practices in this population.

METHODS

An interdisciplinary committee was assembled to answer 12 questions concerning the provision of PN to preterm infants. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) process was used. Questions addressed parenteral macronutrient doses, lipid injectable emulsion (ILE) composition, and clinically relevant outcomes, including PNALD, early childhood growth, and neurodevelopment. Preterm infants with congenital gastrointestinal disorders or infants already diagnosed with necrotizing enterocolitis or PN-associated liver disease (PNALD) at study entry were excluded.

RESULTS

The committee reviewed 2460 citations published between 2001 and 2023 and evaluated 57 clinical trials. For most questions, quality of evidence was very low. Most analyses yielded no significant differences between comparison groups. A multicomponent oil ILE was associated with a reduction in stage 3 or higher retinopathy of prematurity (ROP) compared to an ILE containing 100% soybean oil. For all other questions, expert opinion was provided.

CONCLUSION

Most clinical outcomes were not significantly different between comparison groups when evaluating timing of PN initiation, amino acid dose, and ILE composition. Future clinical trials should standardize outcome definitions to permit statistical conflation of data, thereby permitting more evidence based recommendations in future guidelines. This guideline has been approved by the ASPEN 2022-2023 Board of Directors.

Does Growth Velocity Affect Associations between Birth Weight and Neurodevelopment for Infants Born Very Preterm?

OBJECTIVE

To determine how neonatal growth velocity affects the association between birth weight and neurodevelopmental outcomes in infants born preterm.

STUDY DESIGN

This study is a secondary analysis of the Maternal Omega-3 Supplementation to Reduce Bronchopulmonary Dysplasia in Very Preterm Infants (MOBYDIck) randomized multicenter trial conducted in breastfed infants born at <29 weeks of gestation, whose mothers were supplemented with docosahexaenoic acid or placebo during the neonatal period. Neurodevelopmental outcomes were assessed at 18-22 months of corrected age using the Bayley-III cognitive and language composite scores. The role of neonatal growth velocity was assessed with causal mediation and linear regression models. Subgroup analyses were stratified by birth weight z-score categories (<25th, ≥25th-≤75th, and >75th percentiles).

RESULTS

Neurodevelopmental outcomes were available for 379 children (mean gestational age, 26.7 ± 1.5 weeks). Growth velocity partially mediated the relationships between birth weight and cognitive (β = -1.1; 95% CI, -2.2 to -0.02; P = .05) and language scores (β = -2.1; 95% CI, -3.3 to -0.8; P = .002). An increase by 1 g/kg/day in growth velocity was associated with an increase by 1.1 point in the cognitive score (95% CI, -0.03 to 2.1; P = .06) and 1.9 point in the language score (95% CI, 0.7 to 3.1; P = .001), after adjustment for birth weight z-score. For children with birth weight <25th percentile, a 1 g/kg/day increase in growth velocity was associated with an increase by 3.3 points in the cognitive score (95% CI, 0.5 to 6.0; P = .02) and 4.1 points in the language score (95% CI, 1.3 to 7.0; P = .004).

CONCLUSIONS

Postnatal growth velocity mediated the relationship between birth weight and neurodevelopmental performance, with larger effects for children with lower birth weight.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02371460.

Frühgeborene: Schützen zusätzliche Aminosäuren vor Behinderungen?

Für das fetale Wachstum und die Hirnentwicklung ist eine ausreichende Proteinzufuhr unabdingbar. Es wird angenommen, dass Feten in utero täglich zwischen 3 und 4 Gramm Aminosäuren pro Kilogramm Körpergewicht aufnehmen. Profitieren Frühgeborene mit extrem niedrigem Geburtsgewicht im Hinblick auf die entwicklungsneurologische Prognose, das Wachstum und die neonatale Morbidität von einer erhöhten Aminosäurezufuhr?