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

Development and Validation of an MRI-Based Brain Volumetry Model Predicting Poor Psychomotor Outcomes in Preterm Neonates

Background/Objectives: Infant FreeSurfer was introduced to address robust quantification and segmentation in the infant brain. The purpose of this study is to develop a new model for predicting the long-term neurodevelopmental outcomes of very low birth weight preterm infants using automated volumetry extracted from term-equivalent age (TEA) brain MRIs, diffusion tensor imaging, and clinical information. Methods: Preterm infants hospitalized at Severance Children's Hospital, born between January 2012 and December 2019, were consecutively enrolled. Inclusion criteria included infants with birth weights under 1500 g who underwent both TEA MRI and Bayley Scales of Infant and Toddler Development, Second Edition (BSID-II), assessments at 18-24 months of corrected age (CA). Brain volumetric information was derived from Infant FreeSurfer using 3D T1WI of TEA MRI. Mean and standard deviation of fractional anisotropy of posterior limb of internal capsules were measured. Demographic information and comorbidities were used as clinical information. Study cohorts were split into training and test sets with a 7:3 ratio. Random forest and logistic regression models were developed to predict low Psychomotor Development Index (PDI < 85) and low Mental Development Index (MDI < 85), respectively. Performance metrics, including the area under the receiver operating curve (AUROC), accuracy, sensitivity, precision, and F1 score, were evaluated in the test set. Results: A total of 150 patient data were analyzed. For predicting low PDI, the random forest classifier was employed. The AUROC values for models using clinical variables, MR volumetry, and both clinical variables and MR volumetry were 0.8435, 0.7281, and 0.9297, respectively. To predict low MDI, a logistic regression model was chosen. The AUROC values for models using clinical variables, MR volumetry, and both clinical variables and MR volumetry were 0.7483, 0.7052, and 0.7755, respectively. The model incorporating both clinical variables and MR volumetry exhibited the highest AUROC values for both PDI and MDI prediction. Conclusions: This study presents a promising new prediction model utilizing an automated volumetry algorithm to distinguish long-term psychomotor developmental outcomes in preterm infants. Further research and validation are required for its clinical application.

Brain development using a multicomponent intravenous lipid emulsion in preterm infants

BACKGROUND

Intravenous lipid emulsions are an essential component of nutritional support for very preterm infants. Many neonatal intensive care units have transitioned from traditional soybean oil-only to fish oil-containing multicomponent lipid emulsions, but the neurodevelopmental implications have not been well-explored. The primary aim of this study was to assess extrauterine third trimester brain growth in very preterm infants supported with soybean oil-only compared to fish-oil containing multicomponent lipid emulsions; white matter development and neurobehavioral regulation at term were also investigated.

METHODS

Human milk-fed very preterm infants (born less than or equal to 32 weeks' gestation) receiving either soybean oil-only (before 2019) or multicomponent (after 2019) lipid emulsions underwent quantitative brain MRI (volumetric growth and white matter development) and neurodevelopmental assessment (Neonatal Intensive Care Unit Network Neurobehavioral Scale) at term-equivalent age. Analyses were adjusted for age at birth and term assessments, as well as clinically significant covariates.

RESULTS

92 infants (61 soybean, 31 multicomponent) were included (mean [SD] birth gestational age: 27.3 [2.3] weeks). Soybean oil-only infants demonstrated smaller brainstem volumes (β [95% CI] = -0.5 [-0.8,-0.1], p = .007); additionally less mature white matter development (mean diffusivity [MD, mm2/second x10- 3] and fractional anisotropy [FA]) in the corpus callosum (MD genu: β = 0.10 [0.01, 0.20], p = .04; splenium: β = 0.14 [0.04, 0.24], p = .006), posterior limbs of internal capsule (MD right (R): β = 0.05 [0.02, 0.08], p = .004, left (L): β = 0.04 [0.01, 0.08], p = .01; FA R: β = -0.03 [-0.06, -0.00], p = .03), and brainstem (FA R: β = 0.07 [0.04, 0.10], p < .001, L: β = 0.05 [0.02, 0.09], p = .002); and lower quality of movement (β = -0.54 [-0.97, -0.11], p = .02) and higher state-related stress (β = 1.41 [0.14, 2.83], p = .04).

CONCLUSIONS

Very preterm infants supported with a fish-oil containing multicomponent compared to soybean oil-only lipid emulsion demonstrated improved regional brain growth, as well as evidence of enhanced white matter microstructural organization and neurobehavioral regulation, at term corrected age.

TRIAL REGISTRATION

Clinical trial number: Not applicable.

Maternal high-dose docosahexaenoic acid supplementation and neurodevelopment at 5 Years of preterm children

BACKGROUND & AIMS

Docosahexaenoic acid (DHA) is the most abundant omega-3 fatty acid in the brain and is accumulated by the fetal brain during the last trimester of pregnancy. Our objective was to determine whether high-dose DHA supplementation during the neonatal period, vs. placebo, improves behavioral functioning at 5 years in children born very preterm.

METHODS

This is a follow-up at 5 years corrected age of a subset of children who participated in a multicenter randomized controlled trial. The participants received a high-dose DHA supplementation, or a placebo, through maternal breastmilk until 36 weeks' postmenstrual age. Primary outcome was child behavioral functioning, assessed by the Total Difficulties Score from the Strengths and Difficulties Questionnaire (SDQ). Secondary outcomes included behavioral scores from the SDQ, executive functions assessment and global developmental performance. Neurodevelopmental outcomes were assessed through interviews with parents. Mean differences between DHA and placebo groups were estimated using mixed linear models. Subgroup analyses were conducted for sex and gestational age (GA) at birth.

RESULTS

Among 177 eligible children, 132 (74.6 %) completed neurodevelopmental assessment at 5 years (DHA, N = 64, placebo, N = 68). Total Difficulties Score did not differ between the DHA and placebo groups (mean differences, -0.9 [95 % confidence interval, -2.7 to 0.8], P = 0.30), nor any of the secondary outcomes. There was no significant interaction between treatment groups and sex, nor GA, for the primary outcome. However, significant interactions between treatment groups and sex or GA were found for some secondary outcomes.

CONCLUSIONS

In very preterm infants, high-dose DHA supplementation did not improve behavioral functioning at 5 years.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02371460, https://clinicaltrials.gov/study/NCT02371460.

Home-ics: how experiences of the home impact biology and child neurodevelopmental outcomes

Studies on the -omics of child neurodevelopmental outcomes, e.g. genome, epigenome, microbiome, metabolome, and brain connectome aim to enable data-driven precision health to improve these outcomes, or deliver the right intervention, to the right child, at the right time. However, evidence suggests that neurodevelopmental outcomes are shaped by modifiable socioenvironmental factors. Everyday exposures including family and neighbourhood-level socioeconomic status, housing conditions, and interactions with those living in the home, are strongly associated with child health and have been suggested to alter -omics. Our aim was to review and understand the biological pathways by which home factors contribute to child neurodevelopment outcomes. We review studies suggestive of the home factors contributing to neurodevelopmental outcomes that encompass the hypothalamic-pituitary-adrenal axis, the brain, the gut-brain-axis, and the immune system. We thus conceptualize home-ics as the study of how the multi-faceted living environment can impact neurodevelopmental outcomes through biology and highlight the importance of targeting the modifiable aspects of a child's home to optimize outcomes. We encourage clinicians and health care providers to routinely assess home factors in patient encounters, and counsel families on modifiable aspects of the home. We conclude by discussing clinical and policy implications and future research directions of home-ics. IMPACT: Home-ics can be conceptualized as the study of how home factors may shape child neurodevelopmental outcomes through altering biology. Targeting modifiable aspects of a child's home environment (e.g. parenting style, early intervention, enriched environment) may lead to improved neurodevelopmental outcomes. Clinicians should routinely assess home factors and counsel families on modifiable aspects of the home.

Improving growth in preterm infants through nutrition: a practical overview

The primary purpose of this practical overview is to provide a practical update on appropriate nutritional strategies to improve growth in preterm infants. Current recommendations for improving preterm growth concern both macronutrients and micronutrients, with tailored nutrition since the first days of life, particularly when fetal growth restriction has been reported. Human milk is undoubtedly the best nutrition for all newborns, but, in some populations, if not adequately fortified, it does not adequately support their growth. In all preterms, growth should be correctly monitored weekly to intercept a negative trend of growth and implement nutritional strategies to avoid growth restriction. Similarly, growth should be accurately supported and monitored after discharge to improve long-term health consequences.

Infant attachment does not depend on neonatal amygdala and hippocampal structure and connectivity

Infant attachment is an antecedent of later socioemotional abilities, which can be adversely affected by preterm birth. The structural integrity of amygdalae and hippocampi may subserve attachment in infancy. We aimed to investigate associations between neonatal amygdalae and hippocampi structure and their whole-brain connections and attachment behaviours at nine months of age in a sample of infants enriched for preterm birth. In 133 neonates (median gestational age 32 weeks, range 22.14-42.14), we calculated measures of amygdala and hippocampal structure (volume, fractional anisotropy, mean diffusivity, neurite dispersion index, orientation dispersion index) and structural connectivity, and coded attachment behaviours (distress, fretfulness, attentiveness to caregiver) from responses to the Still-Face Paradigm at nine months. After multiple comparisons correction, there were no significant associations between neonatal amygdala or hippocampal structure and structural connectivity and attachment behaviours: standardised β values - 0.23 to 0.18, adjusted p-values > 0.40. Findings indicate that the neural basis of infant attachment in term and preterm infants is not contingent on the structure or connectivity of the amygdalae and hippocampi in the neonatal period, which implies that it is more widely distributed in early life and or that network specialisation takes place in the months after hospital discharge.

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.

Breast Milk Exposure is Associated With Cortical Maturation in Preterm Infants

OBJECTIVE

Breast milk exposure is associated with improved neurocognitive outcomes following preterm birth but the neural substrates linking breast milk with outcome are uncertain. We tested the hypothesis that high versus low breast milk exposure in preterm infants results in cortical morphology that more closely resembles that of term-born infants.

METHODS

We studied 135 preterm (<32 weeks' gestation) and 77 term infants. Feeding data were collected from birth until hospital discharge and brain magnetic resonance imaging (MRI) was performed at term-equivalent age. Cortical indices (volume, thickness, surface area, gyrification index, sulcal depth, and curvature) and diffusion parameters (fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [RD], axial diffusivity [AD], neurite density index [NDI], and orientation dispersion index [ODI]) were compared between preterm infants who received exclusive breast milk for <75% of inpatient days, preterm infants who received exclusive breast milk for ≥75% of inpatient days and term-born controls. To investigate a dose response effect, we performed linear regression using breast milk exposure quartile weighted by propensity scores.

RESULTS

In preterm infants, high breast milk exposure was associated with reduced cortical gray matter volume (d = 0.47, 95% confidence interval [CI] = 0.14 to 0.94, p = 0.014), thickness (d = 0.42, 95% CI = 0.08 to 0.84, p = 0.039), and RD (d = 0.38, 95% CI = 0.002 to 0.77, p = 0.039), and increased FA (d = -0.38, 95% CI = -0.74 to -0.01, p = 0.037) after adjustment for age at MRI, which was similar to the cortical phenotype observed in term-born controls. Breast milk exposure quartile was associated with cortical volume (ß = -0.192, 95% CI = -0.342 to -0.042, p = 0.017), FA (ß = 0.223, 95% CI = 0.075 to 0.372, p = 0.007), and RD (ß = -0.225, 95% CI = -0.373 to -0.076, p = 0.007) following adjustment for age at birth, age at MRI, and weighted by propensity scores, suggesting a dose effect.

INTERPRETATION

High breast milk exposure following preterm birth is associated with a cortical imaging phenotype that more closely resembles the brain morphology of term-born infants and effects appear to be dose-dependent. ANN NEUROL 2023;93:591-603.

MRI-based brain volumes of preterm infants at term: a systematic review and meta-analysis

BACKGROUND

MRI allows a detailed assessment of brain structures in preterm infants, outperforming cranial ultrasound. Neonatal MR-based brain volumes of preterm infants could serve as objective, quantitative and reproducible surrogate parameters of early brain development. To date, there are no reference values for preterm infants' brain volumes at term-equivalent age.

OBJECTIVE

Systematic review of the literature to determine reference ranges for MRI-based brain volumes of very preterm infants at term-equivalent age.

METHODS

PubMed Database was searched on 6 April 2020 for studies reporting MR-based brain volumes on representative unselected populations of very preterm and/or very low birthweight infants examined at term equivalent age (defined as 37-42 weeks mean postmenstrual age at MRI). Analyses were limited to volumetric parameters reported in >3 studies. Weighted mean volumes and SD were both calculated and simulated for each parameter.

RESULTS

An initial 367 publications were identified. Following application of exclusion criteria, 13 studies from eight countries were included for analysis, yielding four parameters. Weighted mean total brain volume was 379 mL (SD 72 mL; based on n=756). Cerebellar volume was 21 mL (6 mL; n=791), cortical grey matter volume 140 mL (47 mL; n=572) and weighted mean volume of unmyelinated white matter was 195 mL (38 mL; n=499).

CONCLUSION

This meta-analysis reports pooled data on several brain and cerebellar volumes which can serve as reference for future studies assessing MR-based volumetric parameters as a surrogate outcome for neurodevelopment and for the interpretation of individual or cohort MRI-based volumetric findings.

Serum docosahexaenoic acid levels are associated with brain volumes in extremely preterm born infants

BACKGROUND

Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for fetal brain growth and development. Our aim was to evaluate the association between serum DHA and AA levels and brain volumes in extremely preterm infants.

METHODS

Infants born at <28 weeks gestational age in 2013-2015, a cohort derived from a randomized controlled trial comparing two types of parenteral lipid emulsions, were included (n = 90). Serum DHA and AA levels were measured at postnatal days 1, 7, 14, and 28, and the area under the curve was calculated. Magnetic resonance (MR) imaging was performed at term-equivalent age (n = 66), and volumes of six brain regions were automatically generated.

RESULTS

After MR image quality assessment and area under the curve calculation, 48 infants were included (gestational age mean [SD] 25.5 [1.4] weeks). DHA levels were positively associated with total brain (B = 7.966, p = 0.012), cortical gray matter (B = 3.653, p = 0.036), deep gray matter (B = 0.439, p = 0.014), cerebellar (B = 0.932, p = 0.003), and white matter volume (B = 3.373, p = 0.022). AA levels showed no association with brain volumes.

CONCLUSIONS

Serum DHA levels during the first 28 postnatal days were positively associated with volumes of several brain structures in extremely preterm infants at term-equivalent age.

IMPACT

Higher serum levels of DHA in the first 28 postnatal days are positively associated with brain volumes at term-equivalent age in extremely preterm born infants. Especially the most immature infants suffer from low DHA levels in the first 28 postnatal days, with little increase over time. Future research is needed to explore whether postnatal fatty acid supplementation can improve brain development and may serve as a nutritional preventive and therapeutic treatment option in extremely preterm infants.

How does the convergence of prematurity and congenital heart disease impact the developing brain?

Prematurity and congenital heart disease (CHD) are individually associated with increased risk of brain injury and adverse neurodevelopmental outcomes. Delayed brain development in newborns with CHD has been documented to begin in utero and predisposes newborns with CHD to brain injury. Little is known about the combined risks when prematurity and CHD co-occur. The purpose of this review is to highlight the unique vulnerability of preterm newborns with CHD to brain dysmaturation and brain injury, and the urgent need for prospective research.

Parenteral lipid emulsions in the preterm infant: current issues and controversies

Parenteral lipid emulsions are a necessary component of nutrition for extremely low gestational age newborns until adequate levels of enteral intake are established. Historically, Intralipid, a 100% soybean oil emulsion, has filled this role. Newer multicomponent lipid emulsions containing a mixture of other oils, including olive oil and fish oil, are now available as options, although the regulatory approval for use in neonates varies worldwide. When dosed at currently published recommendations, each of these lipid emulsions meets total fat and energy requirements without a risk of essential fatty acid deficiency. Thus, when choosing which lipid emulsion to provide, the answer must be based on the metabolic differences induced as a result of these fatty acid-rich emulsions and whether the emulsions provide a health advantage or pose a health risk. The questions of induced fatty acid profiles, health benefit and health risk are discussed sequentially for multicomponent lipid emulsions. Despite the growing acceptance of multicomponent lipid emulsions, there is concern regarding changes in blood fatty acid levels and potential health risk without strong evidence of benefit. There remains no ideal parenteral lipid emulsion option for the preterm infant. Standardising future animal and human studies in lipid delivery with the inclusion of lipid metabolism data will iteratively provide answers to inform the optimal lipid emulsion for the preterm infant.

Smoflipid Is Better Than Lipofundin for Long-Term Neurodevelopmental Outcomes in Preterm Infants

Neurodevelopmental morbidities developed more commonly in low-birth-weight premature infants. We sought to determine the effects of different lipid emulsions on the neurodevelopmental outcomes of children born prematurely. This retrospective cross-sectional study had two intervention legs, Lipofundin^® MCT/LCT (LIPO) versus Smoflipid^® (SMOF), which are mainly differentiated by fish oil. Data of premature neonates born between 2001 and 2015 from the research database of Chang Gung Memorial Hospital with corresponding individual medical records up to July 2020 were analyzed. Long-term neurodevelopmental outcomes were defined by the international classification of disease codes −9 or −10. The prevalence of diseases was compared between LIPO and SMOF groups at five and five years old and further analyzed by stratification of 1500 g birth weight. The LIPO and SMOF groups each included 1120 neonates. Epilepsy, cerebral palsy, developmental disorder and attention-deficit hyperactivity disorder (ADHD) were significantly decreased at age two years in the SMOF group, and epilepsy, language delay (LD), ADHD and autism spectrum disorder (ASD) were significantly decreased in the SMOF group at age five years. In children with birth weight < 1500 g, ADHD was decreased in the SMOF group at ages two and five years, and ASD was decreased in the SMOF group at age five years. In children with birth weight ≥ 1500 g, epilepsy, LD and ADHD were decreased in the SMOF group at age two years. LD was decreased in the SMOF group at age five years. We conclude that lipid emulsions with fish oil improve the neurodevelopmental outcomes of children born prematurely.

Lipid Intake and Neurodevelopment in Preterm Infants

Preterm infants are born before the critical period of lipid accretion and brain development that occurs during the third trimester of pregnancy. Dietary lipids serve as an important source of energy and are involved in complex processes that are essential for normal central nervous system development. In addition to traditional neurodevelopmental testing, novel quantitative magnetic resonance imaging (MRI) techniques are now available to evaluate the impact of nutritional interventions on early preterm brain development. Trials of long-chain polyunsaturated fatty acid supplementation have yielded inconsistent effects on neurodevelopmental outcomes and quantitative MRI findings. Recent studies using quantitative MRI suggest a positive impact of early lipid intake on brain volumes and white matter microstructural organization by term-equivalent age.

Acute symptomatic neonatal seizures, brain injury, and long-term outcome: The role of neuroprotective strategies

INTRODUCTION

Neonatal seizures are frequent but underdiagnosed manifestations of acute brain dysfunction and an important contributor to unfavorable outcomes. Etiology and severity of brain injury are the single strongest outcome determinants.

AREAS COVERED

The authors will discuss the prognostic role of acute symptomatic seizures versus brain injury and the main neuroprotective and neurorestorative strategies for full-term and preterm infants.

EXPERT OPINION

Prolonged acute symptomatic seizures likely contribute to long-term outcomes by independently adding further brain injury to initial insults. Correct timing and dosing of therapeutic interventions, depending on etiology and gestational ages, need careful evaluation. Although promising strategies are under study, the only standard of care is whole-body therapeutic hypothermia in full-term newborns with hypoxic-ischemic encephalopathy.

Early Lipid Intake Improves Cerebellar Growth in Very Low-Birth-Weight Preterm Infants

BACKGROUND

Despite recent advances in nutrition practice in the neonatal intensive care unit, infants remain at high risk for growth restriction following preterm birth. Additionally, optimal values for macronutrient administration, especially lipid intake, have yet to be established for preterm infants in the extrauterine environment.

METHODS

We studied preterm infants born at very low-birth weight (VLBW, <1500 g) and ≤32 weeks' gestation. Cumulative macronutrient (carbohydrate, lipid, protein, energy) intake in the first 2 and 4 weeks of life was compared with total and regional brain volumes on magnetic resonance imaging (MRI) obtained at term-equivalent age. Preterm infants had no structural brain injury on conventional MRI.

RESULTS

In a cohort of 67 VLBW infants, cumulative lipid intake in the first 2 weeks of life was positively associated with significantly greater cerebellar volume (β = 95.8; P = .01) after adjusting for weight gain, gestational age at birth, and postmenstrual age at MRI. Cumulative lipid (β = 36.1, P = .01) and energy (β = 3.1; P = .02) intake in the first 4 weeks of life were both significantly associated with greater cerebellar volume. No relationship was seen between carbohydrate or protein intake in the first month of life and cerebral volume at term-equivalent age.

CONCLUSION

Early cumulative lipid intake in the first month of life is associated with significantly greater cerebellar volume by term-equivalent age in very premature infants. Our findings emphasize the importance of early, aggressive nutrition interventions to optimize cerebellar development in VLBW infants.

NICU Diet, Physical Growth and Nutrient Accretion, and Preterm Infant Brain Development

Half of very preterm infants experience neurodevelopmental impairments after NICU discharge. These adverse outcomes result in part from abnormal brain development and injury that occur during the NICU hospitalization. Although many factors influence infant brain development, nutritional determinants are of particular interest because they are highly modifiable within clinical care. Physical growth of preterm infants in the NICU continues to lag behind the reference fetus, suggesting reduced nutrient accretion during a critical period for brain development. Nutrient accretion is driven by intake of specific nutrients such as macro- and micronutrients as well as non-nutritional factors such as systemic inflammation. Most often, anthropometric indicators, such as weight, length, and head circumference, are used as proxies for nutrient accretion. A limitation of weight is that it does not differentiate the healthy growth of specific organs and tissues from excess fat accumulation. Body length provides information about skeletal growth, and linear growth stunting predicts neurodevelopmental impairment. Head circumference is only a crude proxy for brain size. More recently, application of new technologies such as air displacement plethysmography and magnetic resonance imaging has allowed the direct estimation of lean tissue accretion and brain growth in the NICU. These newer techniques can facilitate research to improve our understanding of the links among the NICU diet, inflammation, physical growth, and brain development. These new measures may also be relevant within clinical care to identify infants who may benefit from specific interventions to enhance nutrient accretion and brain development.

Bermúdez M, Campoy C. Influence of a Functional Nutrients-Enriched Infant Formula on Language Development in Healthy Children at Four Years Old

Nutrition during early life is essential for brain development and establishes the basis for cognitive and language skills development. It is well established that breastfeeding, compared to formula feeding, has been traditionally associated with increased neurodevelopmental scores up to early adulthood. We analyzed the long-term effects of a new infant formula enriched with bioactive compounds on healthy children's language development at four years old. In a randomized double-blind COGNIS study, 122 children attended the follow-up call at four years. From them, 89 children were fed a standard infant formula (SF, n = 46) or an experimental infant formula enriched with functional nutrients (EF, n = 43) during their first 18 months of life. As a reference group, 33 exclusively breastfed (BF) were included. Language development was assessed using the Oral Language Task of Navarra-Revised (PLON-R). ANCOVA, chi-square test, and logistic regression models were performed. EF children seemed to show higher scores in use of language and oral spontaneous expression than SF children, and both SF and EF groups did not differ from the BF group. Moreover, it seems that SF children were more frequently categorized into "need to improve and delayed" in the use of language than EF children, and might more frequently present "need to improve and delayed" in the PLON-R total score than BF children. Finally, the results suggest that SF children presented a higher risk of suffering language development than BF children. Secondary analysis also showed a slight trend between low socioeconomic status and poorer language skills. The functional compound-enriched infant formula seems to be associated with beneficial long-term effects in the development of child's language at four years old in a similar way to breastfed infants.

A More Comprehensive Approach to the Neuroprotective Potential of Long-Chain Polyunsaturated Fatty Acids in Preterm Infants Is Needed-Should We Consider Maternal Diet and the n-6:n-3 Fatty Acid Ratio?

There is growing evidence that long-chain polyunsaturated fatty acids (LCPUFAs) are of importance for normal brain development. Adequate supply of LCPUFAs may be particularly important for preterm infants, because the third trimester is an important period of brain growth and accumulation of arachidonic acid (n-6 LCPUFA) and docosahexaenoic acid (n-3 LCPUFA). Fatty acids from the n-6 and n-3 series, particularly, have important functions in the brain as well as in the immune system, and their absolute and relative intakes may alter both the risk of impaired neurodevelopment and response to injury. This narrative review focuses on the potential importance of the n-6:n-3 fatty acid ratio in preterm brain development. Randomized trials of post-natal LCPUFA supplementation in preterm infants are presented. Pre-clinical evidence, results from observational studies in preterm infants as well as studies in term infants and evidence related to maternal diet during pregnancy, focusing on the n-6:n-3 fatty acid ratio, are also summarized. Two randomized trials in preterm infants have compared different ratios of arachidonic acid and docosahexaenoic acid intakes. Most of the other studies in preterm infants have compared formula supplemented with arachidonic acid and docosahexaenoic acid to un-supplemented formula. No trial has had a comprehensive approach to differences in total intake of both n-6 and n-3 fatty acids during a longer period of neurodevelopment. The results from preclinical and clinical studies indicate that intake of LCPUFAs during pregnancy and post-natal development is of importance for neurodevelopment and neuroprotection in preterm infants, but the interplay between fatty acids and their metabolites is complex. The best clinical approach to LCPUFA supplementation and n-6 to n-3 fatty acid ratio is still far from evident, and requires in-depth future studies that investigate specific fatty acid supplementation in the context of other fatty acids in the diet.

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.

Dysmaturation of Premature Brain: Importance, Cellular Mechanisms, and Potential Interventions

Prematurity, especially preterm birth (less than 32 weeks' gestation), is common and associated with high rates of both survival and neurodevelopmental disability, especially apparent in cognitive spheres. The neuropathological substrate of this disability is now recognized to be related to a variety of dysmaturational disturbances of the brain. These disturbances follow initial brain injury, particularly cerebral white matter injury, and involve many of the extraordinary array of developmental events active in cerebral white and gray matter structures during the premature period. This review delineates these developmental events and the dysmaturational disturbances that occur in premature infants. The cellular mechanisms involved in the genesis of the dysmaturation are emphasized, with particular focus on the preoligodendrocyte. A central role for the diffusely distributed activated microglia and reactive astrocytes in the dysmaturation is now apparent. As these dysmaturational cellular mechanisms appear to occur over a relatively long time window, interventions to prevent or ameliorate the dysmaturation, that is, neurorestorative interventions, seem possible. Such interventions include pharmacologic agents, especially erythropoietin, and particular attention has also been paid to such nutritional factors as quality and source of milk, breastfeeding, polyunsaturated fatty acids, iron, and zinc. Recent studies also suggest a potent role for interventions directed at various experiential factors in the neonatal period and infancy, i.e., provision of optimal auditory and visual exposures, minimization of pain and stress, and a variety of other means of environmental behavioral enrichment, in enhancing brain development.

Plasma cholesterol levels and brain development in preterm newborns

BACKGROUND

To assess whether postnatal plasma cholesterol levels are associated with microstructural and macrostructural regional brain development in preterm newborns.

METHODS

Sixty preterm newborns (born 24-32 weeks gestational age) were assessed using MRI studies soon after birth and again at term-equivalent age. Blood samples were obtained within 7 days of each MRI scan to analyze for plasma cholesterol and lathosterol (a marker of endogenous cholesterol synthesis) levels. Outcomes were assessed at 3 years using the Bayley Scales of Infant Development, Third Edition.

RESULTS

Early plasma lathosterol levels were associated with increased axial and radial diffusivities and increased volume of the subcortical white matter. Early plasma cholesterol levels were associated with increased volume of the cerebellum. Early plasma lathosterol levels were associated with a 2-point decrease in motor scores at 3 years.

CONCLUSIONS

Higher early endogenous cholesterol synthesis is associated with worse microstructural measures and larger volumes in the subcortical white matter that may signify regional edema and worse motor outcomes. Higher early cholesterol is associated with improved cerebellar volumes. Further work is needed to better understand how the balance of cholesterol supply and endogenous synthesis impacts preterm brain development, especially if these may be modifiable factors to improve outcomes.

Cerebellar hypoplasia of prematurity: Causes and consequences

As magnetic resonance imaging has been increasingly used to study brain injury and brain development in premature newborns, the prevalence of cerebellar abnormalities is increasingly recognized. The preterm cerebellum is highly vulnerable to a number of insults during its critical phase of growth and development throughout the period of prematurity and beyond. Direct cerebellar injury and additional factors such as supratentorial brain injury and glucocorticoid exposure adversely impact cerebellar growth and, consequently, increase the risk of neurodevelopmental disabilities. In this chapter the causes and consequences of cerebellar hypoplasia of prematurity are reviewed.