Improving head growth in preterm infants--a randomised controlled trial II: MRI and developmental outcomes in the first year

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.

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.

Association between preterm infant size at 1 year and ADHD later in life: data from 1993 and 2004 Pelotas Birth Cohorts

The objective of this study is to examine the association between preterm infants' size at 1 year and attention-deficit/hyperactivity disorder (ADHD) assessed categorically and dimensionally in childhood and adolescence. We studied infants born < 37 weeks' gestation from two Brazilian birth cohorts (n = 653). ADHD was evaluated using the Development and Well-Being Assessment (DAWBA) interview at the age of 6 years in one cohort and by a structured interview according to DSM-5 criteria at 18 years in the other one. The presence of child attention difficulties was measured by the Strengths and Difficulties Questionnaire (SDQ) at 6 and 11 years in the 2004 and 1993 cohorts, respectively. We estimated associations of weight, length, head circumference, and BMI z-scores at 1-year chronological age with ADHD using Poisson Regression Model; and with attention difficulties using Linear Regression, adjusting for covariates. Mean birth weight was 2500 g and gestational age was 34.5 weeks. The aggregated ADHD prevalence in the two cohorts was 2.7%, and the median score for attention difficulties was 3.0. We found that increased head circumference at 1 year was associated with a lower risk of ADHD diagnosis (RR = 0.7, 95% CI 0.4, 0.9; p = 0.04 per standard deviation difference) and with fewer dimensional attention symptoms. In sensitivity analysis with other mental disorders, head circumference was associated with depression, but not with anxiety. Our findings emphasize poor head growth in the first year of life as a potential determinant of attentional difficulties in the preterm infant population.

The influence of nutrition on white matter development in preterm infants: a scoping review

White matter (WM) injury is the most common type of brain injury in preterm infants and is associated with impaired neurodevelopmental outcome (NDO). Currently, there are no treatments for WM injury, but optimal nutrition during early preterm life may support WM development. The main aim of this scoping review was to assess the influence of early postnatal nutrition on WM development in preterm infants. Searches were performed in PubMed, EMBASE, and COCHRANE on September 2022. Inclusion criteria were assessment of preterm infants, nutritional intake before 1 month corrected age, and WM outcome. Methods were congruent with the PRISMA-ScR checklist. Thirty-two articles were included. Negative associations were found between longer parenteral feeding duration and WM development, although likely confounded by illness. Positive associations between macronutrient, energy, and human milk intake and WM development were common, especially when fed enterally. Results on fatty acid and glutamine supplementation remained inconclusive. Significant associations were most often detected at the microstructural level using diffusion magnetic resonance imaging. Optimizing postnatal nutrition can positively influence WM development and subsequent NDO in preterm infants, but more controlled intervention studies using quantitative neuroimaging are needed. IMPACT: White matter brain injury is common in preterm infants and associated with impaired neurodevelopmental outcome. Optimizing postnatal nutrition can positively influence white matter development and subsequent neurodevelopmental outcome in preterm infants. More studies are needed, using quantitative neuroimaging techniques and interventional designs controlling for confounders, to define optimal nutritional intakes in preterm infants.

Early-Life Slow Enteral Feeding Progression Pattern Is Associated with Longitudinal Head-Size Growth Faltering and Neurodevelopmental Impairment Outcomes in Extremely Preterm Infants

OBJECTIVE

To determine whether feeding progression patterns in the first eight postnatal weeks, depicted by clustering analysis of daily enteral feeding volume, are associated with longitudinal head-circumference (HC) growth and neurodevelopmental outcomes in extremely preterm (EP) infants.

METHODS

200 infants who were admitted at gestational ages 23-27 weeks between 2011 and 2018; survived to discharge; and underwent longitudinal HC growth measurements at birth, term-equivalent age (TEA), corrected age (CA) 6-month, 12-month, and 24-month; and neurodevelopmental assessment using the Bayley Scales of Infant Development at CA 24 months were included for analysis.

RESULTS

kmlShape analysis identified two distinct enteral feeding progression patterns: fast progression in 131 (66%) infants and slow progression in 69 (34%) infants. Compared to the fast progression group, the slow progression group showed significantly lower daily enteral volumes after day 13, was older in postnatal age reaching full feeding, had a higher rate of Delta z scores of HC (zHC) < -1 (p < 0.001) between birth and TEA, and displayed lower longitudinal zHC from TEA to CA 24 months. The slow progression group also showed higher rates of microcephaly [42% vs. 16%, p < 0.001; adjusted odd ratio (aOR): 3.269, p = 0.001] and neurodevelopmental impairment (NDI) (38% vs. 19%, p = 0.007; aOR: 2.095, p = 0.035) at CA 24 months. For NDI, the model including feeding progression patterns showed a lower Akaike information criterion score and a better goodness of fit than the model that did not include feeding patterns.

CONCLUSION

Characterizing feeding progression pattern may help identify EP infants at high-risk of head-size growth faltering and NDI at early childhood.

Impact of time to full enteral feeding on long-term neurodevelopment without mediating by postnatal growth failure in very-low-birth-weight-infants

This study aimed to determine if time to achieve full enteral feeding (TFF) directly impacted long-term neurodevelopmental delay (NDD) and whether long-term postnatal growth failure (PGF) was a mediator of this association in very-low-birth-weight (VLBW) infants. Using prospectively collected cohort data from the Korean Neonatal Network, we included eligible VLBW infants who achieved TFF at least once and classified enrolled infants into four groups using exposure severity (P1 to P4 as TFF < 16, 16-30, 31-45, and > 45 postnatal days, respectively). After adjusting for confounding variables, survival without NDD was significantly decreased in P4 infants compared with that in P2 infants. P1 infants had a lower risk of weight and height PGF than P2 infants; however, P4 infants had higher risks of height and head circumference PGF than P2 infants. Weight and height PGF were significantly associated with an increased risk of NDD. In mediation analysis, early and delayed TFF revealed direct positive and negative impacts, respectively, on the risk of NDD without mediation by PGF. TFF impacted survival without NDD, and PGF did not mediate this association in VLBW infants. Additionally, these results can be translated into evidence-based quality improvement practice.

Relationship between early nutrition and deep gray matter and lateral ventricular volumes of preterm infants at term-equivalent age

BACKGROUND

The survival of preterm infants has improved over the last decade, but impaired brain development leading to poor neurological outcomes is still a major comorbidity associated with prematurity. The aim of this study was to evaluate the effect of nutrition on neurodevelopment in preterm infants and identify markers for improved outcomes.

METHODS

Totally 67 premature infants with a gestational age of 24-34 weeks and a birth weight of 450-2085 g were included. Clinical parameters and documented diet were collected from medical records. The nutritional analysis comprised the protein, fat, carbohydrate, and energy intake during different time spans. Brain development was assessed by determining deep gray matter (DGM; basal ganglia and thalamus) and lateral ventricular (LV) volumes as measured on cerebral magnetic resonance imaging scans obtained at term-equivalent age (TEA), and potential associations between nutrition and brain volumetrics were detected by regression analysis.

RESULTS

We observed a negative correlation between mean daily protein intake in the third postnatal week and MRI-measured DGM volume at TEA (P = 0.007). In contrast, head circumference at a corrected age of 35 weeks gestation (P < 0.001) and mean daily fat intake in the fourth postnatal week (P = 0.004) were positively correlated with DGM volume. Moreover, mean daily carbohydrate intake in the first postnatal week (P = 0.010) and intraventricular hemorrhage (P = 0.003) were revealed as independent predictors of LV volume.

CONCLUSION

The study emphasizes the importance of nutrition for brain development following preterm birth.

Growth in extremely preterm children born in England in 1995 and 2006: the EPICure studies

OBJECTIVES

To determine growth outcomes at 11 years of age in children born <27 weeks of gestation in England in 2006 (EPICure2) and to compare growth from birth to 11 years of age for births<26 weeks with those in England in 1995 (EPICure).

METHODS

200 EPICure2 children assessed at 11 years alongside 143 term-born controls. Growth measures from birth to 11 years were compared for births<26 weeks between EPICure2 (n=112) and EPICure (n=176). Growth parameter z-scores were derived from 1990 UK standards.

RESULTS

Among EPICure2 children, mean z-scores for height and weight were close to the population standards (0.08 and 0.18 SD, respectively) but significantly below those of controls: difference in mean (Δ) z-scores for weight -0.42 SD (95% CI -0.68 to -0.17), for height -0.45 SD (-0.70 to -0.20) and for head circumference (HC) -1.05 SD (-1.35 to -0.75); mean body mass index (BMI) z-score in EPICure2 children was 0.18 SD, not significantly different from controls (0.43 SD, p=0.065). Compared with EPICure, EPICure2 children born <26 weeks at 11 years had higher z-scores for weight (Δ 0.72 (0.47, 0.96)), height (Δ 0.55 (0.29, 0.81)) and BMI (Δ 0.56 (0.24, 0.87)), which were not fully explained by perinatal/demographic differences between eras. Weight catch-up was greater from term-age to 2.5/3 years in EPICure2 than in EPICure (1.25 SD vs 0.53 SD; p<0.001). Poor HC growth was observed in EPICure2, unchanged from EPICure.

CONCLUSIONS

Since 1995, childhood growth in weight, height and BMI have improved for births <26 weeks of gestation, but there was no improvement in head growth.

Extra-uterine growth restriction in preterm infants: Neurodevelopmental outcomes according to different definitions

AIM

Extra-uterine Growth Restriction (EUGR) is common among preterm infants. Two types of EUGR definitions are still now available: cross-sectional definitions and longitudinal ones. In a cohort of very preterm infants, we aimed to evaluate which definition could better predict neurodevelopmental outcomes at 2 years of corrected age. We used Italian Neonatal Study Charts (INeS) growth charts and INTERGROWTH-21st (IG-21) standard charts and compared results.

METHOD

We restrospectively collected data from clinical charts of 324 preterm newborns with a gestational age ≤30 weeks born from 2012 to 2017. Then we compared forty-eight definitions (24 cross-sectional and 24 longitudinal) of EUGR, in term of neurodevelopmental outcomes at 2 years of corrected age.

RESULTS

We included in the study 254 preterm infants, whose clinical information met the enrolment criteria. Nineteen out of 48 definitions of EUGR were significantly predictive both for Griffith's Development Quotient (GDQ) and Neurodevelopment Impairment (NDI). Among these, longitudinal definitions appeared to have a higher negative predictive value for NDI than cross-sectional ones. Furthermore, infants with EUGR appeared to have a lower cognitive score than their peers without EUGR.

INTERPRETATION

A loss of Zs > 1 SDS in weight and head circumference, calculated from when physiological weight loss is over and identified as soon as possible rather than at discharge, better predicts neurodevelopmental outcomes of preterm infants.

Human induced pluripotent stem cell derived hepatocytes provide insights on parenteral nutrition associated cholestasis in the immature liver

Parenteral nutrition-associated cholestasis (PNAC) significantly limits the safety of intravenous parenteral nutrition (PN). Critically ill infants are highly vulnerable to PNAC-related morbidity and mortality, however the impact of hepatic immaturity on PNAC is poorly understood. We examined developmental differences between fetal/infant and adult livers, and used human induced pluripotent stem cell-derived hepatocyte-like cells (iHLC) to gain insights into the contribution of development to altered sterol metabolism and PNAC. We used RNA-sequencing and computational techniques to compare gene expression patterns in human fetal/infant livers, adult liver, and iHLC. We identified distinct gene expression profiles between the human feta/infant livers compared to adult liver, and close resemblance of iHLC to human developing livers. Compared to adult, both developing livers and iHLC had significant downregulation of xenobiotic, bile acid, and fatty acid metabolism; and lower expression of the sterol metabolizing gene ABCG8. When challenged with stigmasterol, a plant sterol found in intravenous soy lipids, lipid accumulation was significantly higher in iHLC compared to adult-derived HepG2 cells. Our findings provide insights into altered bile acid and lipid metabolizing processes in the immature human liver, and support the use of iHLC as a relevant model system of developing liver to study lipid metabolism and PNAC.

Effect of first-month head-size growth trajectory on cognitive outcomes in preterm infants

BACKGROUND

To examine whether the patterns of head-size growth trajectory in the first month after birth are associated with different susceptibility to cognitive impairment outcomes at age 24 months.

METHODS

This retrospective cohort study included 590 infants of very-preterm survivors born between 2001 and 2016 receiving neurodevelopmental assessment at age 24 months. 403 children were enrolled for analysis after excluding infants with small-for-gestational age and severe brain injury. The head circumference (HC) growth evaluated weekly in the first month after birth compared to the at-birth HC was analyzed using group-based trajectory modeling. Neurocognition outcomes were determined as normal, borderline delay, or impaired using the Bayley Scales of Infant Development.

RESULTS

The HC growth dynamics in the first month after birth showed three trajectory patterns: delayed catch-up (31.5%), slow catch-up (54.0%), and fast catch-up (14.5%), which significantly corresponded to different rates of impaired cognition at 19.5%, 6.0%, and 8.5%, respectively (p < 0.001). While 60% of the fast catch-up group had normal cognition, only one-third of the delayed catch-up group showed normal cognition. Three neonatal risk factors, gestational age (p = 0.006), respiratory distress syndrome requiring surfactant therapy (p = 0.012), and hemodynamically significant patent ductus arteriosus requiring intervention (p = 0.047) significantly affected HC growth trajectory patterning that led to cognitive impairment outcomes at follow-up.

CONCLUSIONS

Preterm infants with delayed catch-up of head-size growth in the first month of age is susceptible to cognitive impairment outcome.

Energy-enhanced parenteral nutrition and neurodevelopment of preterm newborns: A cohort study

OBJECTIVES

Preterm births are at higher risk for neurodevelopment (NDV) disabilities. To limit long-term consequences, guidelines recommend aggressive parenteral nutrition (PN) soon after birth. The aim of this study was to examine the effects of energy-enhanced PN in the first week of life on long-term NDV in preterm neonates.

METHODS

We compared two cohorts of newborns (group A: energy-enhanced PN and group B: energy-standard PN) with different energy intake in the first 7 d of life (DoL) given by PN with the same protein amount, to study the influences of an energy-enhanced PN on NDV at 24 mo of life evaluated with the Bayley Scale of Infant Development-III edition.

RESULTS

We analyzed 51 newborns (A: n = 24 versus B: n = 27). The two cohorts were similar in baseline characteristics (gestational age group A 29 wk, 95% confidence interval [CI], 28-30 wk versus group B 29 wk, 95% CI, 28-30 wk; birth weight A: 1214 g, 95% CI, 1062-1365 g versus B 1215 g, 95% CI, 1068-1363 g; boys A 62.5% versus B 55.6%). Infants in cohort B showed significantly (P < 0.05) better gross motor, total scaled, and total composite motor scores (A: 8 (1) versus B 9 (2); A 17 (4) versus B 19 (5); A 91 (12) versus B 97 (15); respectively). Cohort A showed a higher percentage of infants with delayed socioemotional competence (A 30.4% versus B 7.7%, P < 0.05). No differences were found in growth parameters at 24 mo of life. Linear regression analysis showed that socioemotional competence and motor score were negatively associated with energy intake of the first 7 DoL given by PN.

CONCLUSIONS

A more aggressive PN strategy results in lower motor score and socioemotional competence performance at 24 mo of life. More caution might be advocated for an energy-enhanced PN protocol, particularly in neonates with lower birth weight, for long-term NDV in preterm neonates.

Head Circumference Growth Is Enhanced by SMOFlipid in Preterm Neonates

BACKGROUND

Suboptimal fat intake during the early postnatal weeks significantly affects brain growth and maturation. Studies to date have focused on the quantity rather than the quality of fat intake.

OBJECTIVE

We hypothesized that early nutrition of premature neonates should also include optimization of the type of fat intake, and thus those receiving SMOFlipid, a balanced multicomponent lipid emulsion, would have improved head growth as measured by head circumference (HC) at discharge.

STUDY DESIGN

We retrospectively reviewed HC in infants weighing <1,500 g who were hospitalized for two or more weeks during a 20-month period, in which all preterm infants received fat as Lipofundin, and the following 20-month period, in which all such infants received SMOFlipid.Lipids were dosed up to 3 g/kg/day and reduced as enteral nutrition progressed. Parenteral fish oil (Omegaven) was permitted as rescue therapy during both periods.

RESULTS

Period 2 infants had better head growth (0.79 [0.69,0.90] vs. 0.75 [0.64,0.86] cm/week; p = 0.0158). More infants reached discharge with an HC of ≥50 percentile (51 vs. 31%; p = 0.0007), and fewer infants had an HC of ≤3 percentile (11 vs. 14%; p = 0.023). Median length of stay was reduced by more than 1 week.A multivariable regression was performed using the weekly increase in HC as the dependent variable, and the time epoch, birth weight, gestational age, hospitalization days, and gender as independent variables. Only the time epoch and days of hospitalization were significant (both p < 0.0001).

CONCLUSION

Our data offer preliminary evidence of improved brain growth in those receiving a balanced lipid emulsion as compared with a soybean oil emulsion.

Effect of Fortification of Breast Milk in Conjugation with Protein Supplement on Neurodevelopment of Preterm Low Birth Weight Infants at 3 Years

Introduction:

Choice of appropriate nutrition has a special place, which variations in dietary nutrient can potentially be involved in growth deficits in preterm neonates.

Aim:

to investigate the effect of protein supplementation in very low birth weight (VLBW= birth weight under 1500 grams) infants on neurological growth in the third year of birth.

Material and Methods:

We investigated neurological growth in two groups of control and intervention (each group, n= 18 subjects). The intervention group includes 3-year-old children who weighting less than 1200 grams at birth and have received protein supplementation at the course of NICU hospitalization, protein was added to maternal milk when the amount of milk reaches to 100 cc/kg/day, at this time parenteral nutrition was discontinued and the volume of feeding was increased 20cc/kg/day until reached to 150-180cc/kg/day. We also added the fortifier to breast milk at this time (FMS- Aptamil- DANON). The fortification and the protein supplementation were stopped when the weight of the baby reached to 1500 grams. The control group was fed similar to the intervention group, without protein supplemental intake. Neurodevelopmental outcomes were evaluated using ASQ, NEWSHA and BINS tools.

Results:

There was no significant difference between the mean head circumference in the two groups (p=0.209). There was no significant relationship between neurological growth rate evaluated by BINS tool in two groups (p=0.266). There was a significant correlation between the neurological development assessed by the ASQ tool in the areas of communication (p=0.014) and gross motor (p=0.001) in the two groups, however, no significant relationship was found in terms of fine motor (p=0.63), problem solving (p=0.07) and personal-social relationships in both groups (p=0.152). There was a significant correlation between neurological development evaluated using the NEWSHA tool in terms of auditory (p=0.031), verbal language (p=0.024), cognitive (p=0.007), social connection (p=0.034) and motor (p=0.002) in the two groups.

Conclusion:

Protein intake in preterm infants didn’t reveal long term effects on the growth of head circumference. Moreover, it was capable of improving neurological growth in the areas of communication and gross motor (based on the ASQ) and auditory, verbal language, cognitive, social connection, and motor (based on the NEWSHA).

Head circumference, apolipoprotein E genotype and cognition in the Bavarian School Sisters Study

Background

The apolipoprotein E (APOE) ɛ4 allele is correlated with an earlier onset of Alzheimer's disease symptoms; larger head circumference has been associated with an individual resilience against cognitive impairment.

Methods

We explored if larger head circumference attenuates the effect of the APOE ɛ4 allele on cognition in 380 Catholic sisters covering the spectrum from normal cognitive performance to severe dementia.

Results

Linear regression analysis, adjusting for risk factors for cognitive decline, revealed that APOE ɛ4 was correlated with worse cognition and that larger head circumference attenuated the negative effect of the ɛ4 allele on cognitive performance.

Conclusion

Larger head circumference (i.e. larger brain size) seems to be associated with greater resilience against genetic determinants of cognitive impairment, possibly due to enhanced brain or cognitive reserve.

Maternal Dietary Intake of Omega-3 Fatty Acids Correlates Positively with Regional Brain Volumes in 1-Month-Old Term Infants

Maternal nutrition is an important factor for infant neurodevelopment. However, prior magnetic resonance imaging (MRI) studies on maternal nutrients and infant brain have focused mostly on preterm infants or on few specific nutrients and few specific brain regions. We present a first study in term-born infants, comprehensively correlating 73 maternal nutrients with infant brain morphometry at the regional (61 regions) and voxel (over 300 000 voxel) levels. Both maternal nutrition intake diaries and infant MRI were collected at 1 month of life (0.9 ± 0.5 months) for 92 term-born infants (among them, 54 infants were purely breastfed and 19 were breastfed most of the time). Intake of nutrients was assessed via standardized food frequency questionnaire. No nutrient was significantly correlated with any of the volumes of the 61 autosegmented brain regions. However, increased volumes within subregions of the frontal cortex and corpus callosum at the voxel level were positively correlated with maternal intake of omega-3 fatty acids, retinol (vitamin A) and vitamin B12, both with and without correction for postmenstrual age and sex (P < 0.05, q < 0.05 after false discovery rate correction). Omega-3 fatty acids remained significantly correlated with infant brain volumes after subsetting to the 54 infants who were exclusively breastfed, but retinol and vitamin B12 did not. This provides an impetus for future larger studies to better characterize the effect size of dietary variation and correlation with neurodevelopmental outcomes, which can lead to improved nutritional guidance during pregnancy and lactation.

Nutrition and the developing brain: the road to optimizing early neurodevelopment: a systematic review

BACKGROUND

Neonatal intensive care practices have resulted in marked improvements in the survival of premature infants; however, they remain at significant risk for adverse neurodevelopmental outcomes. The impact of current nutritional practices on brain development following early extra-uterine exposure in premature infants is not well known.

METHODS

We performed a systematic review to investigate nutritional effects on postnatal brain development in healthy term and prematurely born infants utilizing advanced magnetic resonance imaging tools.

RESULTS

Systematic screen yielded 595 studies for appraisal. Of these, 22 total studies were selected for inclusion in the review, with findings summarized in a qualitative, descriptive fashion.

CONCLUSION

Fat and energy intake are associated with improved brain volume and development in premature infants. While breast milk intake and long-chain polyunsaturated fatty acid supplementation has been proven beneficial in term infants, the impact in preterm infants is less well understood.

Relationships Between Early Neonatal Nutrition and Neurodevelopment at School Age in Children Born Very Preterm

OBJECTIVES

The aim of this study was to determine whether a new nutrition protocol designed to increase early protein intakes while reducing fluid volume in infants born very preterm was associated with altered neurodevelopment and growth in childhood.

METHODS

A retrospective, observational cohort study of children born <30 weeks' gestation or <1500 g and admitted to the neonatal unit, National Women's Hospital, Auckland, New Zealand, before and after a change in nutrition protocol. The primary outcome was neurodevelopmental impairment at 7 years (any of Wechsler Intelligence Scale for Children full scale IQ < 85, Movement Assessment Battery for Children-2 total score ≤5th centile, cerebral palsy, blind, or deaf requiring aids). Outcomes were compared between groups and for the overall cohort using generalized linear regression, adjusted for sex and birth weight z score.

RESULTS

Of 201 eligible children, 128 (64%) were assessed (55/89 [62%] exposed to the old nutrition protocol, 73 of 112 [65%] to the new protocol). Children who experienced the new protocol received more protein, less energy, and less carbohydrate in postnatal days 1 to 7. Neurodevelopmental impairment was similar at 7 years (30/73 [41%] vs 25/55 [45%], adjusted odds ratio [AOR] [95% confidence interval] 0.78 [0.35-1.70], P = 0.55), as was the incidence of cerebral palsy (AOR 7.36 [0.88-61.40], P = 0.07). Growth and body composition were also similar between groups. An extra 1 g/kg parenteral protein intake in postnatal days 1 to 7 was associated with a 27% increased odds of cerebral palsy (AOR 1.27 [1.03-1.57], P = 0.006).

CONCLUSIONS

Higher early protein intakes do not change overall rates of neurodevelopmental impairment or growth at 7 years. Further research is needed to determine the effects of higher early parenteral protein intake on motor development.

The Influence of Early Nutrition on Brain Growth and Neurodevelopment in Extremely Preterm Babies: A Narrative Review

Extremely preterm babies are at increased risk of less than optimal neurodevelopment compared with their term-born counterparts. Optimising nutrition is a promising avenue to mitigate the adverse neurodevelopmental consequences of preterm birth. In this narrative review, we summarize current knowledge on how nutrition, and in particular, protein intake, affects neurodevelopment in extremely preterm babies. Observational studies consistently report that higher intravenous and enteral protein intakes are associated with improved growth and possibly neurodevelopment, but differences in methodologies and combinations of intravenous and enteral nutrition strategies make it difficult to determine the effects of each intervention. Unfortunately, there are few randomized controlled trials of nutrition in this population conducted to determine neurodevelopmental outcomes. Substantial variation in reporting of trials, both of nutritional intakes and of outcomes, limits conclusions from meta-analyses. Future studies to determine the effects of nutritional intakes in extremely preterm babies need to be adequately powered to assess neurodevelopmental outcomes separately in boys and girls, and designed to address the many potential confounders which may have clouded research findings to date. The development of minimal reporting sets and core outcome sets for nutrition research will aid future meta-analyses.

Longitudinal changes in the gut microbiome of infants on total parenteral nutrition

BACKGROUND

Animal studies suggest that total parenteral nutrition (TPN) may alter bacterial colonization of the intestinal tract and contribute to complications. Progressive changes in gut microbiome of infants receiving TPN are not well understood.

METHODS

Infants with and without TPN/soy lipid were enrolled in a prospective, longitudinal study. Weekly fecal samples were obtained for the first 4 weeks of life. High throughput pyrosequencing of 16S rDNA was used for compositional analysis of the gut microbiome.

RESULTS

47 infants were eligible for analyses, 25 infants received TPN, and 22 infants did not (control). Although similar between TPN and control groups in the first week, fecal bacterial alpha diversity was significantly lower in the TPN group compared to controls at week 4 (Shannon index 1.0 vs 1.5, P-value = 0.03). The TPN group had significantly lower Bacteroidetes and higher Verrucomicrobia abundance compared to controls (P-values < 0.05), and these differences became more pronounced over time. At the genus level, TPN was associated with lower abundance of Bacteroides and Bifidobacterium in all weeks.

CONCLUSIONS

TPN is associated with significant loss of biodiversity and alterations in the pattern of gut microbial colonization of infants over time. TPN-associated dysbiosis may predispose infants to adverse NICU outcomes.

Impact of early protein and energy intakes on neurodevelopment at 2 years of corrected age in very low birth weight infants: A single-center observational study

Introduction

Aggressive nutritional strategy, particularly enhancing early provision of energy and protein, has appeared to reduce postnatal growth failure and improve later developmental outcomes. But the amount of macronutrients required remains unclear. The aim of this study was to investigate the impact of protein and energy intakes during the first two weeks after birth on neurodevelopmental outcomes.

Methods

This retrospective cohort study of very low birth weight infants born between January 2012 and December 2015 was conducted at one tertiary neonatal intensive care unit. The primary outcome was a neurodevelopmental impairment (NDI) at 2 years corrected age defined by a cerebral palsy or a 24 month Ages and Stages Questionnaires score on any of the five domains lower than 2 standard deviation below the mean score. Multivariable logistic regression analysis was used to adjust for perinatal and postnatal confounders.

Results

Among 245 (73%) infants discharged home alive, 159 (65%) had follow-up at 2 years. Infants with NDI (55/159, 35%) were more likely male gender (67.3% versus 46.2%, P = 0.02) and experienced more patent ductus arteriosus (PDA) ligation (20% versus 5.8%, P = 0.01) than control. After adjusting for confounders, first-week protein intake (OR: 2.27 [CI: 1.07–5.14]; P < 0.05), second-week non-protein energy intake (OR: 1.03 [CI: 1.01–1.05]; P < 0.01) and PDA ligation (OR: 6.81 [1.80–28.46]; P < 0.01) had significant independent association with higher likelihood of NDI at 2 years.

Conclusion

Providing nutrition above the optimal level may not be beneficial and may even be harmful. These results confirm the recent recommendation to decrease amino acid intakes published in the latest ESPGHAN guidelines.

Establishment of an ideal gut microbiota to boost healthy growth of neonates

For decades, supporting the optimal growth of low birth weight (LBW) infants has been considered one of the most important paediatric challenges, despite advances in neonatal intensive care technology and nutrition interventions. Since gut microbiota affects such diverse phenotypes in adults, the difference in gut microbiota composition between normal infants and LBW infants raises the possibility of gut microbiota playing an important role in different growth rates of neonates. Based on the concept that probiotics are generally beneficial to the health, numerous studies have been made on probiotics as a supplement to the diet of the LBW infants. However, clinical results on the effects of probiotics on LBW infant growth are either inconsistent or contradictory with each other, and thus the contribution of gut microbiota in neonatal growth has remained inconclusive. In this review, recent researches on neonatal gut microbiota are discussed to develop a new strategy for targeting gut microbiota as a solution to growth retardation in LBW infants. We also discuss how to establish the ideal gut microbiota to support optimal growth of LBW infants.

"You have to keep your nerve on a DMC." Challenges for Data Monitoring Committees in neonatal intensive care trials: Qualitative accounts from the BRACELET Study

Background

Data Monitoring Committees (DMCs) are essential to the good conduct of many trials. Typically they comprise a small expert group which monitors safety, efficacy, progress and early outcome data as trials recruit. DMCs can recommend protocol revisions and early stopping of a trial. As DMC meetings usually consider unblinded interim data confidentially, their deliberations are seldom exposed to research scrutiny. Although there have been some case studies from trials from mixed specialties which offer insights into some of the common issues faced by DMCs, we have, however, little empirical information about the challenges faced within specific clinical settings.

Methods

In-depth interviews with participants in the BRACELET Study on death and bereavement in neonatal intensive care trials produced qualitative accounts of experiences and views of a subgroup of 18 DMC members. These interviews explored views of DMC members in relation to the clinical context of neonatal intensive care and the conduct of neonatal intensive care trials.

Results

Interviewees felt that an understanding of both the neonatal intensive care setting and population was crucial in a DMC. They considered the neonatal intensive care research population especially vulnerable, and that outcomes that included both death and severe disability raised particular challenges rarely faced in other settings. In exploring these key outcomes they were mindful of the need to meet high scientific standards and the needs of babies in the trials and their families. DMC members discussed particular difficulties around the composite outcome of death and severe disability, especially when mortality data were available long before data on longer term disability. While statistical stopping guidance is helpful, DMC members described decisions about stopping, revising or continuing a trial being informed by a wider set of considerations and discussions than a pre-set p value. These included potentially competing needs of current trial participants and future patients, and reflections on the nature of benefit and harm. Given their cognisance of the potential impact and consequences of the decisions made by DMCs in this setting of life, death, and disability, interviewees commonly used the imagery of bravery, and described DMCs either holding or losing their nerve.

Conclusions

DMCs for trials in other fields may also face difficult ethical trade-offs in monitoring composite outcomes. The experience from this sample of DMC members suggest that for neonatal intensive care trials there are some very specific challenges seldom faced elsewhere. The vulnerability of the population, and the different timescales for essential data becoming available to inform decisions, presented particular challenges. We suggest that it is important to consider the challenges raised in other settings to better understand the complex work of these committees and to prepare future generations of DMC members.

Body length and occipitofrontal circumference may be good indicators of neurodevelopment in very low birthweight infants - secondary publication

AIM

The aim of this study was to predict the neurological prognosis of very low birthweight (VLBW) infants. We examined the relationship between nutritional status, brain volume measured by magnetic resonance imaging (MRI) and anthropometric measurements of VLBW infants at term-equivalent age (TEA).

METHODS

We evaluated 27 VLBW infants, born at Showa University Hospital in Japan between April 2012 and August 2013, who underwent brain MRI at TEA. Based on their clinical data, we analysed their protein and energy intake.

RESULTS

Median values for the 27 VLBW infants were as follows: gestational age, 29.7 weeks; birthweight 1117 g; protein intake 2.7 g/kg/day and energy intake 97.9 kcal/kg/day. At TEA, the standard deviation scores (SDSs) of body weight, body length and the occipitofrontal circumference (OFC) were -0.8, -1.4 and 0.7, respectively. Multiple regression analysis revealed that the SDSs of body length and the OFC at TEA were significant determinants of white matter volume, but that the SDS of body weight at TEA was not.

CONCLUSION

Our findings suggest that the SDSs of body length and the OFC at TEA may be better indicators than body weight for predicting the development of the central nervous system in VLBW infants receiving nutritional management.

Higher versus lower amino acid intake in parenteral nutrition for newborn infants

BACKGROUND

Sick newborn and preterm infants frequently are not able to be fed enterally, necessitating parenteral fluid and nutrition. Potential benefits of higher parenteral amino acid (AA) intake for improved nitrogen balance, growth, and infant health may be outweighed by the infant's ability to utilise high intake of parenteral AA, especially in the days after birth.

OBJECTIVES

The primary objective is to determine whether higher versus lower intake of parenteral AA is associated with improved growth and disability-free survival in newborn infants receiving parenteral nutrition.Secondary objectives include determining whether:• higher versus lower starting or initial intake of amino acids is associated with improved growth and disability-free survival without side effects;• higher versus lower intake of amino acids at maximal intake is associated with improved growth and disability-free survival without side effects; and• increased amino acid intake should replace non-protein energy intake (glucose and lipid), should be added to non-protein energy intake, or should be provided simultaneously with non-protein energy intake.We conducted subgroup analyses to look for any differences in the effects of higher versus lower intake of amino acids according to gestational age, birth weight, age at commencement, and condition of the infant, or concomitant increases in fluid intake.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (2 June 2017), MEDLINE (1966 to 2 June 2017), Embase (1980 to 2 June 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 2 June 2017). We also searched clinical trials databases, conference proceedings, and citations of articles.

SELECTION CRITERIA

Randomised controlled trials of higher versus lower intake of AAs as parenteral nutrition in newborn infants. Comparisons of higher intake at commencement, at maximal intake, and at both commencement and maximal intake were performed.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality, and extracted data from included studies. We performed fixed-effect analyses and expressed treatment effects as mean difference (MD), risk ratio (RR), and risk difference (RD) with 95% confidence intervals (CIs) and assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

Thirty-two studies were eligible for inclusion. Six were short-term biochemical tolerance studies, one was in infants at > 35 weeks' gestation, one in term surgical newborns, and three yielding no usable data. The 21 remaining studies reported clinical outcomes in very preterm or low birth weight infants for inclusion in meta-analysis for this review.Higher AA intake had no effect on mortality before hospital discharge (typical RR 0.90, 95% CI 0.69 to 1.17; participants = 1407; studies = 14; I² = 0%; quality of evidence: low). Evidence was insufficient to show an effect on neurodevelopment and suggest no reported benefit (quality of evidence: very low). Higher AA intake was associated with a reduction in postnatal growth failure (< 10th centile) at discharge (typical RR 0.74, 95% CI 0.56 to 0.97; participants = 203; studies = 3; I² = 22%; typical RD -0.15, 95% CI -0.27 to -0.02; number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 4 to 50; quality of evidence: very low). Subgroup analyses found reduced postnatal growth failure in infants that commenced on high amino acid intake (> 2 to ≤ 3 g/kg/day); that occurred with increased amino acid and non-protein caloric intake; that commenced on intake at < 24 hours' age; and that occurred with early lipid infusion.Higher AA intake was associated with a reduction in days needed to regain birth weight (MD -1.14, 95% CI -1.73 to -0.56; participants = 950; studies = 13; I² = 77%). Data show varying effects on growth parameters and no consistent effects on anthropometric z-scores at any time point, as well as increased growth in head circumference at discharge (MD 0.09 cm/week, 95% CI 0.06 to 0.13; participants = 315; studies = 4; I² = 90%; quality of evidence: very low).Higher AA intake was not associated with effects on days to full enteral feeds, late-onset sepsis, necrotising enterocolitis, chronic lung disease, any or severe intraventricular haemorrhage, or periventricular leukomalacia. Data show a reduction in retinopathy of prematurity (typical RR 0.44, 95% CI 0.21 to 0.93; participants = 269; studies = 4; I² = 31%; quality of evidence: very low) but no difference in severe retinopathy of prematurity.Higher AA intake was associated with an increase in positive protein balance and nitrogen balance. Potential biochemical intolerances were reported, including risk of abnormal blood urea nitrogen (typical RR 2.77, 95% CI 2.13 to 3.61; participants = 688; studies = 7; I² = 6%; typical RD 0.26, 95% CI 0.20 to 0.32; number needed to treat for an additional harmful outcome (NNTH) 4; 95% CI 3 to 5; quality of evidence: high). Higher amino acid intake in parenteral nutrition was associated with a reduction in hyperglycaemia (> 8.3 mmol/L) (typical RR 0.69, 95% CI 0.49 to 0.96; participants = 505; studies = 5; I² = 68%), although the incidence of hyperglycaemia treated with insulin was not different.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that higher AA intake in parenteral nutrition does not affect mortality. Very low-quality evidence suggests that higher AA intake reduces the incidence of postnatal growth failure. Evidence was insufficient to show an effect on neurodevelopment. Very low-quality evidence suggests that higher AA intake reduces retinopathy of prematurity but not severe retinopathy of prematurity. Higher AA intake was associated with potentially adverse biochemical effects resulting from excess amino acid load, including azotaemia. Adequately powered trials in very preterm infants are required to determine the optimal intake of AA and effects of caloric balance in parenteral nutrition on the brain and on neurodevelopment.

Nutrient Intake in the First Two Weeks of Life and Brain Growth in Preterm Neonates

BACKGROUND

Optimizing early nutritional intake in preterm neonates may promote brain health and neurodevelopment through enhanced brain maturation. Our objectives were (1) to determine the association of energy and macronutrient intake in the first 2 weeks of life with regional and total brain growth and white matter (WM) maturation, assessed by 3 serial MRI scans in preterm neonates; (2) to examine how critical illness modifies this association; and (3) to investigate the relationship with neurodevelopmental outcomes.

METHODS

Forty-nine preterm neonates (21 boys, median [interquartile range] gestational age: 27.6 [2.3] weeks) were scanned serially at the following median postmenstrual weeks: 29.4, 31.7, and 41. The total brain, basal nuclei, and cerebellum were semiautomatically segmented. Fractional anisotropy was extracted from diffusion tensor imaging data. Nutritional intake from day of life 1 to 14 was monitored and clinical factors were collected.

RESULTS

Greater energy and lipid intake predicted increased total brain and basal nuclei volumes over the course of neonatal care to term-equivalent age. Similarly, energy and lipid intake were significantly associated with fractional anisotropy values in selected WM tracts. The association of ventilation duration with smaller brain volumes was attenuated by higher energy intake. Brain growth predicted psychomotor outcome at 18 months' corrected age.

CONCLUSIONS

In preterm neonates, greater energy and enteral feeding during the first 2 weeks of life predicted more robust brain growth and accelerated WM maturation. The long-lasting effect of early nutrition on neurodevelopment may be mediated by enhanced brain growth. Optimizing nutrition in preterm neonates may represent a potential avenue to mitigate the adverse brain health consequences of critical illness.

Postnatal polyunsaturated fatty acids associated with larger preterm brain tissue volumes and better outcomes

BackgroundHuman studies investigating the link between postnatal polyunsaturated fatty acids and preterm brain growth are limited, despite emerging evidence of potential effects on outcomes.MethodsSixty preterm neonates <32 weeks gestational age with magnetic resonance imaging (MRI) scanning at near-birth and near-term age were assessed for brain tissue volumes, including cortical gray matter, white matter, deep gray matter, cerebellum, brainstem, and ventricular cerebrospinal fluid. Red blood cell fatty acid content was evaluated within 1 week of each MRI scan. Neurodevelopmental outcome at 30-36 months corrected age was assessed.ResultsAdjusting for potential confounders, higher near-birth docosahexaenoic acid levels are associated with larger cortical gray matter, deep gray matter, and brainstem volumes and higher near-term levels with larger deep gray matter, cerebellar, and brainstem volumes at near-term age; lower near-birth linoleic acid levels are correlated with larger white matter volume at near-term age. By 30-36 months corrected age, larger cortical and deep gray matter, cerebellar, and brainstem volumes by term age are associated with improved language scores and larger cerebellar and brainstem volumes with improved motor scores.ConclusionSpecific polyunsaturated fatty acid levels have differential and time-dependent associations with brain region growth. Larger brain volumes are associated with improved outcomes at preschool age.

Effects of early nutrition and growth on brain volumes, white matter microstructure, and neurodevelopmental outcome in preterm newborns

BackgroundThis study aimed to investigate the effect of nutrition and growth during the first 4 weeks after birth on cerebral volumes and white matter maturation at term equivalent age (TEA) and on neurodevelopmental outcome at 2 years' corrected age (CA), in preterm infants.MethodsOne hundred thirty-one infants born at a gestational age (GA) <31 weeks with magnetic resonance imaging (MRI) at TEA were studied. Cortical gray matter (CGM) volumes, basal ganglia and thalami (BGT) volumes, cerebellar volumes, and total brain volume (TBV) were computed. Fractional anisotropy (FA) in the posterior limb of internal capsule (PLIC) was obtained. Cognitive and motor scores were assessed at 2 years' CA.ResultsCumulative fat and enteral intakes were positively related to larger cerebellar and BGT volumes. Weight gain was associated with larger cerebellar, BGT, and CGM volume. Cumulative fat and caloric intake, and enteral intakes were positively associated with FA in the PLIC. Cumulative protein intake was positively associated with higher cognitive and motor scores (all P<0.05).ConclusionOur study demonstrated a positive association between nutrition, weight gain, and brain volumes. Moreover, we found a positive relationship between nutrition, white matter maturation at TEA, and neurodevelopment in infancy. These findings emphasize the importance of growth and nutrition with a balanced protein, fat, and caloric content for brain development.

Exploring the multiple-hit hypothesis of preterm white matter damage using diffusion MRI

Background

Preterm infants are at high risk of diffuse white matter injury and adverse neurodevelopmental outcome. The multiple hit hypothesis suggests that the risk of white matter injury increases with cumulative exposure to multiple perinatal risk factors. Our aim was to test this hypothesis in a large cohort of preterm infants using diffusion weighted magnetic resonance imaging (dMRI).

Methods

We studied 491 infants (52% male) without focal destructive brain lesions born at < 34 weeks, who underwent structural and dMRI at a specialist Neonatal Imaging Centre. The median (range) gestational age (GA) at birth was 30^+ 1 (23^+ 2–33^+ 5) weeks and median postmenstrual age at scan was 42^+ 1 (38–45) weeks. dMRI data were analyzed using tract based spatial statistics and the relationship between dMRI measures in white matter and individual perinatal risk factors was assessed. We tested the hypothesis that increased exposure to perinatal risk factors was associated with lower fractional anisotropy (FA), and higher radial, axial and mean diffusivity (RD, AD, MD) in white matter. Neurodevelopmental performance was investigated using the Bayley Scales of Infant and Toddler Development, Third Edition (BSITD-III) in a subset of 381 infants at 20 months corrected age. We tested the hypothesis that lower FA and higher RD, AD and MD in white matter were associated with poorer neurodevelopmental performance.

Results

Identified risk factors for diffuse white matter injury were lower GA at birth, fetal growth restriction, increased number of days requiring ventilation and parenteral nutrition, necrotizing enterocolitis and male sex. Clinical chorioamnionitis and patent ductus arteriosus were not associated with white matter injury. Multivariate analysis demonstrated that fetal growth restriction, increased number of days requiring ventilation and parenteral nutrition were independently associated with lower FA values. Exposure to cumulative risk factors was associated with reduced white matter FA and FA values at term equivalent age were associated with subsequent neurodevelopmental performance.

Conclusion

This study suggests multiple perinatal risk factors have an independent association with diffuse white matter injury at term equivalent age and exposure to multiple perinatal risk factors exacerbates dMRI defined, clinically significant white matter injury. Our findings support the multiple hit hypothesis for preterm white matter injury.

•

White matter injury was assessed in 491 preterm infants at term equivalent age.

•

Aberrant white matter development was associated with several perinatal factors.

•

Our findings support the multiple hit hypothesis for preterm brain injury.

Nutrition after preterm birth and adult neurocognitive outcomes

Background

Preterm birth (<37 gestational weeks) poses a risk of poorer neurocognitive functioning. Faster growth after preterm birth predicts better cognitive abilities and can be promoted through adequate nutrition, but it remains unknown whether variations in nutrient intakes translate into long-term benefits for neurodevelopment.

Methods

In 86 participants of the Helsinki Study of Very Low Birth Weight Adults (birthweight <1500g), we examined if higher intakes of energy, macronutrients, and human milk during the first nine weeks after preterm birth predict performance in tests of cognitive ability at 25.1 years of age (SD = 2.1).

Results

10 kcal/kg/day higher total energy intake at 3 to 6 weeks of age was associated with 0.21 SD higher adult IQ (95% Confidence Interval [CI] 0.07–0.35). Higher carbohydrate and fat intake at 3–6 weeks, and higher energy intake from human milk at 3–6 and at 6–9 weeks were also associated with higher adult IQ: these effect sizes ranged from 0.09 SD (95% CI 0.01–0.18) to 0.34 SD (0.14–0.54) higher IQ, per one gram/kg/day more carbohydrate and fat, and per 10 kcal/kg/day more energy from human milk. Adjustment for neonatal complications attenuated the associations: intraventricular hemorrhage, in particular, was associated with both poorer nutrition and poorer IQ.

Conclusion

In preterm neonates with very low birth weight, higher energy and human milk intake predict better neurocognitive abilities in adulthood. To understand the determinants of these infants' neurocognitive outcome, it seems important to take into account the role of postnatal nutrition, not just as an isolated exposure, but as a potential mediator between neonatal illness and long-term neurodevelopment.

Early Nutritional Interventions for Brain and Cognitive Development in Preterm Infants: A Review of the Literature

Adequate nutrition is important for neurodevelopmental outcomes in preterm-born infants. In this review, we aim to summarize the current knowledge on nutritional interventions initiated during the hospital stay targeting brain and cognitive development benefits in preterm human infants. Studies can broadly be split in general dietary intervention studies and studies investigating specific nutrients or nutritional supplements. In general, mother's breast milk was reported to be better for preterm infants' neurodevelopment compared to infant formula. The differences in methodologies make it difficult to conclude any effects of interventions with individual nutrients. Only protein and iron level studies showed some consistent findings regarding optimal doses; however, confirmatory studies are needed. This review does not support some widely accepted associations, such as that between long-chain polyunsaturated fatty acid supplementation and visual development. Clear nutritional recommendations cannot be made based on this review. However, the type of infant nutrition (i.e., breast milk versus formula or donor milk), the timing of the nutritional intervention, and the dose of the nutrient/supplement have been found to be relevant factors in determining the success of nutritional intervention studies in preterm infants.

The early postnatal nutritional intake of preterm infants affected neurodevelopmental outcomes differently in boys and girls at 24 months

Aim

This study assessed whether increased amino acid and energy intake in preterm infants during the first week of life was associated with improved neurodevelopment at the corrected age (CA) of 24 months.

Methods

We evaluated preterm infants from two consecutive cohorts in 2004 (Cohort 1) and 2005 (Cohort 2) with different nutritional intakes in the Netherlands. Nutritional intake and growth were recorded until week 5 and after discharge. Neurodevelopment was determined using the Bayley Scales of Infant Development – Second Edition at a CA of 24 months.

Results

Compared to Cohort 1 (n = 56), Cohort 2 (n = 56) received higher nutritional intake during week 1 (p < 0.001). The weight gain in Cohort 2 was higher until week 5, especially among boys (p < 0.002). The mean Mental Developmental Index (MDI) scores did not differ, but Cohort 2 was associated with an increased chance of having an MDI ≥ 85, with an odds ratio of 6.4 and 95% confidence interval (CI) of 1.5–27.4, among all girls with a higher protein intake (5.3, 1.2–23.3). The Psychomotor Developmental Index increased with increasing nutritional intake, especially among boys (β‐coefficient 3.1, 95% CI 0.2–6.0).

Conclusion

Higher nutritional intake was associated with different improvements in growth and neurodevelopment in boys and girls.

Optimizing nutrition of the preterm infant

The goal of nutrition of the preterm infant is to meet the growth rate of the healthy fetus of the same gestational age and to produce the same body composition of the healthy fetus in terms of organ growth, tissue components, and cell number and structure. Nutritional quantity and quality are fundamental for normal growth and development of preterm infants, including neurodevelopmental outcomes. Failure to provide the necessary amounts of all of the essential nutrients has produced not only growth failure, but also increased morbidity and less than optimal neurodevelopment. Growth velocities during the NICU hospitalization period for preterm infants exert a significant effect on neurodevelopmental and anthropometric outcomes. Despite the obvious need for optimal nutrition, growth failure is almost universal among preterm infants. There is every reason, therefore, to optimize nutrition of the preterm infant, in terms of total energy and protein, but also in terms of individual components such as amino acids, specific carbohydrates and lipids, and even oxygen. This review presents scientific rationale for nutrient requirements and practical guidelines and approaches to intravenous and enteral feeding for preterm infants. Intravenous feeding, including amino acids, should be started right after birth at rates that are appropriate for the gestational age of the infant. Enteral feeding should be started as soon as possible after birth, using mother's colostrum and milk as first choices. Enteral feeding should begin with trophic amounts and advanced as rapidly as tolerated, decreasing IV nutrition accordingly, while maintaining nutrient intakes at recommended rates. Feeding protocols are valuable for improving nutrition and related outcomes. Further research is needed to determine the optimal nutrition and rate of growth in preterm infants that will achieve optimal neurocognitive benefits while minimizing the longer-term risk of chronic diseases.

Brain Lesions among Orally Fed and Gastrostomy-Fed Dysphagic Preterm Infants: Can Routine Qualitative or Volumetric Quantitative Magnetic Resonance Imaging Predict Feeding Outcomes?

INTRODUCTION

The usefulness of qualitative or quantitative volumetric magnetic resonance imaging (MRI) in early detection of brain structural changes and prediction of adverse outcomes in neonatal illnesses warrants further investigation. Our aim was to correlate certain brain injuries and the brain volume of feeding-related cortical and subcortical regions with feeding method at discharge among preterm dysphagic infants.

MATERIALS AND METHODS

Using a retrospective observational study design, we examined MRI data among 43 (22 male; born at 31.5 ± 0.8 week gestation) infants who went home on oral feeding or gastrostomy feeding (G-tube). MRI scans were segmented, and volumes of brainstem, cerebellum, cerebrum, basal ganglia, thalamus, and vermis were quantified, and correlations were made with discharge feeding outcomes. Chi-squared tests were used to evaluate MRI findings vs. feeding outcomes. ANCOVA was performed on the regression model to measure the association of maturity and brain volume between groups.

RESULTS

Out of 43 infants, 44% were oral-fed and 56% were G-tube fed at hospital discharge (but not at time of the study). There was no relationship between qualitative brain lesions and feeding outcomes. Volumetric analysis revealed that cerebellum was greater (p < 0.05) in G-tube fed infants, whereas cerebrum volume was greater (p < 0.05) in oral-fed infants. Other brain regions did not show volumetric differences between groups.

CONCLUSION

This study concludes that neither qualitative nor quantitative volumetric MRI findings correlate with feeding outcomes. Understanding the complexity of swallowing and feeding difficulties in infants warrants a comprehensive and in-depth functional neurological assessment.

Early and intensive nutritional strategy combining parenteral and enteral feeding promotes neurodevelopment and growth at 18months of corrected age and 3years of age in extremely low birth weight infants

AIM

To evaluate whether aggressive nutrition can improve long-term neurodevelopmental outcomes and growth in extremely low birth weight (ELBW) infants born appropriate for gestational age (AGA).

METHODS

This single-center cohort study included 137 ELBW AGA infants born in two epochs. The first group received standard nutrition (SN; n=79) consisting of amino acids started at 0.5g/kg/day on Day 4 of life and increased to 1.0g/kg/day. The second aggressive nutrition (AN) group received amino acids started at 1.5-2.0g/kg/day within 24h of life and increased to 3.5g/kg/day. Parenteral and enteral feedings were combined in both groups. Neurodevelopmental outcomes by the Kyoto Scale of Psychological Development and growth were followed up to 18months of corrected age or 3years of age and compared by univariate and multivariate analyses.

RESULTS

Baseline characteristics were similar between the two groups. At 3years of age, AN children had a significantly greater mean value of head circumference, but not length or weight, than SN children (49.1 vs 48.0cm, p=0.014). The cognitive-adaptive (C-A) score in the AN group was also significantly higher than that in the SN group (98.3 vs 91.9 at 18months, p=0.039 and 89.5 vs 83.1 at 3years, p=0.047). AN infants born ≥26weeks of gestation were less likely to develop borderline disability in C-A, language-social and overall developmental scores compared to gestational age-matched SN infants.

CONCLUSION

Parenteral and enteral AN after birth improved the long-term cognitive neurodevelopment in ELBW AGA infants, especially in those born ≥26weeks of gestational age, however results need to be confirmed in a larger, multi-site randomized trial.

Nutrition and neurodevelopmental outcomes in preterm infants: a systematic review

A systematic review with meta-analysis was carried out to investigate the effects of increased nutritional intake, via either macronutrient or multinutrient intervention, during the neonatal period on neurodevelopmental outcomes in infants born at <32 weeks of gestation or weighing <1501 g at birth.

CONCLUSION

Although the relationship remains unclear, increased early nutrition may reduce neurodevelopmental impairment in this group of infants. Future research should focus on using standardised nutritional interventions and an agreed neurodevelopmental assessment battery.

Influence of gestational age and birth weight in neonatal cholesterol response to total parenteral nutrition

BACKGROUND

Premature and critically ill infants receiving total parenteral nutrition (TPN) are at risk for dyslipidemia, and altered cholesterol levels in early life may contribute to later cardiovascular risk. Data regarding plasma cholesterol response to TPN in young infants are lacking.

OBJECTIVE

To determine the changes in plasma cholesterol levels during the first week of life in infants receiving TPN and a comparison group of infants who did not receive TPN during routine care.

METHODS

In a prospective, pilot cohort study, 38 neonates (30 TPN vs. 8 No-TPN) underwent serial blood sampling during the first week of life. Gas chromatography-mass spectrometry was used to measure cholesterol in plasma and TPN administered to study participants.

RESULTS

Baseline cholesterol level was similar between groups. In contrast to infants who did not receive TPN, cholesterol levels during the first week of life were significantly higher than baseline in infants receiving TPN (maximum cholesterol response 34% vs. 103% change from baseline, No-TPN vs. TPN, respectively, P = .036). After adjusting for cumulative cholesterol received by infants receiving TPN, maximum cholesterol response remained inversely related to gestational age and birth weight (P < .05).

CONCLUSION

Plasma cholesterol significantly increases during the first week of life in neonates receiving TPN. A higher cholesterol response was induced by TPN in infants of lower gestational age and birth weight.

Diffusion tensor imaging and behavior in premature infants at 8 years of age, a randomized controlled trial with long-chain polyunsaturated fatty acids

BACKGROUND

Very low birth weight (VLBW, birth weight<1500 g) children have increased risk of behavioral problems. Diffusion tensor imaging (DTI) of the brain shows reduced white matter maturation. Long-chain polyunsaturated fatty acids are hypothesized to improve both myelination and behavioral outcome.

AIMS

To test the hypothesis that postnatal supplementation with docosahexaenoic acid (DHA) and arachidonic acid (AA) to very low birth weight infants would influence cerebral white matter measured by DTI and improve behavioral outcome at 8 years of age.

STUDY DESIGN

Eight-year follow-up of a randomized, double-blinded, placebo-controlled study of postnatal supplementation with DHA and AA to 129 VLBW infants fed human milk.

SUBJECTS

Ninety-eight children (76%) met for follow-up at 8 years.

OUTCOME MEASURES

Cerebral white matter measured by DTI. Behavioral outcome measured by Strengths and Difficulties questionnaire and selected scales from the Child Behavior Checklist.

RESULTS

No significant differences between the intervention group and the control group were found on white matter microstructure or behavioral data. A non-significant finding of higher fractional anisotropy (FA) in a cluster in the corpus callosum of the intervention group is discussed.

CONCLUSIONS

The present study is the first long-term follow-up of a randomized controlled trial with DHA and AA to human milk fed VLBW infants exploring cerebral white matter microstructure measured by DTI and parent-reported behavioral problems. No effects on white matter microstructure or behavioral outcome were observed at 8 years of age.

Nutritional support for premature infants in the neonatal intensive care unit

Nutritional support for premature infants in the neonatal intensive care unit setting is complex. Such infants have conditions unique to this period of the lifespan requiring specialized care management, both of which may impede the provision of adequate nutrition to support basal metabolic needs. Premature infants require optimum nutritional intake to support rapid growth during a time when they are not fully capable of tolerating it. This article reviews developmental anatomy, physiology, and the effect of premature delivery by systems; the challenges of providing adequate nutrition; and current evidence-based strategies to provide nutrition for premature infants during hospitalization.

Long-chain polyunsaturated fatty acids and cognition in VLBW infants at 8 years: an RCT

OBJECTIVE

To test the hypothesis that supplementation with the long chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and arachidonic acid (AA) to very low birth weight (VLBW) infants would improve long-term cognitive functions and influence neuroanatomical volumes and cerebral cortex measured by MRI.

METHODS

The current study is a follow-up of a randomized, double-blinded, placebo-controlled study of supplementation with high-dose DHA (0.86%) and AA (0.91%) to 129 VLBW infants fed human milk. Ninety-eight children participated at 8 years follow-up and completed a broad battery of cognitive tests. Eighty-one children had cerebral MRI scans of acceptable quality.

RESULTS

There were no significant differences between the intervention group and the control group on any of the cognitive measures. Equally, MRI data on segmental brain volumes and cerebral cortex volume, area, and thickness suggested no overall group effect.

CONCLUSIONS

This study is the first long-term follow-up of a randomized controlled trial with supplementation of DHA and AA to human milk fed VLBW infants investigating both cognitive functions and brain macrostructure measured by MRI. No cognitive or neuroanatomical effects of the supplementation were detected at 8 years of age.

Nutritional strategy of early amino acid administration in very low birth weight infants

Relative to a fetus of the same gestational age, very low birth weight (VLBW) infants are more likely to be underfed and to undergo growth restriction during their early hospital stay. The current trend towards "early and aggressive" nutritional strategies in VLBW infants aims to overcome the early nutritional deficiency and thereby boost postnatal catch-up growth, simultaneously improving long-term neurodevelopmental outcomes. Although the minimum starting amino acid (AA) dose to prevent negative nitrogen balance is well established, the upper limit and the rate of increase of early AA doses are controversial. Most randomized controlled trials show that early and high-dose (target, 3.5 to 4.9 g/kg/day) AA regimens, with or without high nonprotein calories, do not improve long-term growth and neurodevelopment. High-dose AA supplementation may lead to early metabolic disturbances and excessive or disproportionate plasma AA levels, particularly in infants of very low gestational age. Further large studies are needed to clarify the optimal strategy for early administration of parenteral AA doses in VLBW infants.

Improved Visual Perception in Very Low Birth Weight Infants on Enhanced Nutrient Supply

BACKGROUND

Optimal nutrient supply to very low birth weight (VLBW: BW <1,500 g) infants is important for growth and neurodevelopment. Growth restriction is common among these infants and may be associated with neurocognitive impairments.

OBJECTIVES

To compare an enhanced nutrient supply to a routine supply given to VLBW infants and to evaluate the effects on visual perception of global form and motion measured by visual event-related potentials (VERP).

METHODS

A total of 50 VLBW infants were randomized to an intervention group that received an increased supply of energy, protein, fat, essential fatty acids, and vitamin A or a control group that received standard nutritional care. At 5 months' corrected age the infants were examined using VERP to investigate the responses to global form and motion. VERP were analysed at the first (f1) and third (f3) harmonics of the stimulus frequency.

RESULTS

Data from 31 subjects were eligible for analysis. The motion VERP responses for the f1 and f3 components were stronger in the area near the posterior midline region in the intervention group compared to the controls in the group analyses (p = 0.02 and p = 0.001, respectively).

CONCLUSION

The results showed a more consistent response to global motion among infants receiving enhanced nutrition. The intervention may have improved visual perception of global motion.

Impact of nutrition on brain development and its neuroprotective implications following preterm birth

The impact of nutrition on brain development in preterm infants has been increasingly appreciated. Early postnatal growth and nutrient intake have been demonstrated to influence brain growth and maturation with subsequent effects on neurodevelopment that persist into childhood and adolescence. Nutrition could also potentially protect against injury. Inflammation and perinatal infection play a crucial role in the pathogenesis of white matter injury, the most common pattern of brain injury in preterm infants. Therefore, nutritional components with immunomodulatory and/or anti-inflammatory effects may serve as neuroprotective agents. Moreover, growing evidence supports the existence of a microbiome-gut-brain axis. The microbiome is thought to interact with the brain through immunological, endocrine, and neural pathways. Consequently, nutritional components that may influence gut microbiota may also exert beneficial effects on the developing brain. Based on these properties, probiotics, prebiotic oligosaccharides, and certain amino acids are potential candidates for neuroprotection. In addition, the amino acid glutamine has been associated with a decrease in infectious morbidity in preterm infants. In conclusion, early postnatal nutrition is of major importance for brain growth and maturation. Additionally, certain nutritional components might play a neuroprotective role against white matter injury, through modulation of inflammation and infection, and may influence the microbiome-gut-brain axis.

Avoiding postnatal undernutrition of VLBW infants during neonatal intensive care: evidence and personal view in the absence of evidence

Inadequate nutrient intakes in the first postnatal weeks play a crucial role in the aetiology of postnatal growth restriction of very low birthweight (VLBW) infants. Efforts to improve early nutrition in these infants led to a significant reduction in postnatal growth failure. Initiation of enhanced parenteral nutrition immediately after birth and utilisation of the large potential of early enteral nutrition seem pivotal. Nevertheless, it remains challenging to further reduce the initial drop in weight and head circumference z-score and to improve body composition and linear growth. This review will summarise data on how near-fetal postnatal weight gain in VLBW infants can be achieved and makes suggestions for early nutrition of VLBW infants.