Contribution of brain size to IQ and educational underperformance in extremely preterm adolescents

Brain volumes and cortical thickness and associations with cognition in children born extremely preterm

BACKGROUND

Children born extremely preterm (EPT) have altered brain volumes and cortical thickness and lower cognition than children born at term. Associations between these have remained largely unexplored, due to the lack of studies focusing on children born EPT.

METHODS

Children underwent brain magnetic resonance imaging (MRI) at term and/or 10 years and cognitive assessments at 12 years. The study comprised of 42 children born EPT and 29 term-born controls with cognitive data and MRI data at 10 years, 25 children born EPT had MRI data at term age and 20 had longitudinal MRI data.

RESULTS

Cognition was positively associated with brain volumes at 10 years, but negatively associated with cortical thickness at 10 years. Most associations between term age brain volumes and cognitive outcomes were non-significant for children born EPT. Growth from term to 10 years in children born EPT was not associated with cognition. Insular volume was positively associated with cognition in children born EPT.

CONCLUSION

Imaging assessments at 10 years had similar associations to cognition in children born EPT and term-born controls. Insular volume could be a biomarker for cognitive outcome. Associations between brain volumetric growth and cognition require further investigation.

IMPACT

This study investigated brain volumes, volumetric growth, and cortical thickness in children born extremely preterm, who have rarely been studied exclusively, and compared the data with term-born controls. In both groups, brain volumes at 10 years were positively associated with cognitive outcome at 12 years, but cortical thickness at 10 years was negatively associated with cognitive outcome at 12 years. Volumetric growth from term age to 10 years was not associated with cognitive outcome in the subset of children born extremely preterm with longitudinal data. Insular volume may be a potential biomarker for cognitive outcome in children born extremely preterm.

Twenty four-hour blood pressure and cognitive outcomes in adolescents born extremely preterm and at term

AIM

To explore the impact of blood pressure on cognitive outcomes at 18 years of age in individuals born extremely preterm (<28 weeks' gestation) and at term (≥37 weeks' gestation).

METHODS

Prospective longitudinal cohort comprising 136 young adults born extremely preterm and 120 matched term controls born in Victoria, Australia in 1991 and 1992. Using linear regression, we analysed the relationships between 24-h mean ambulatory blood pressure, systolic and diastolic hypertension with cognitive outcomes.

RESULTS

For both birth groups combined, higher 24-h mean ambulatory blood pressure and systolic hypertension were associated with similar or worse cognitive outcomes. The strongest relationships were between higher 24-h mean ambulatory blood pressure and systolic hypertension with poorer general intellect, visual learning and visual memory. We found little evidence that relationships between ambulatory blood pressure and cognitive outcomes differed by birth group.

CONCLUSION

Higher 24-h mean ambulatory blood pressure and systolic hypertension were associated with poorer cognitive outcomes in individuals born extremely preterm and at term, particularly in general intelligence and visual memory.

Amygdala volumes and associations with socio-emotional competencies in preterm youth: cross-sectional and longitudinal data

BACKGROUND

Socio-emotional difficulties often result from very preterm (VPT) birth. The amygdala's developmental trajectory, including its nuclei, has been recognized as a significant factor in observed difficulties. This study aims to assess the relationship between amygdala volume and socio-emotional competencies in VPT children and adolescents.

METHODS

Socio-emotional competencies were assessed, and amygdala volumes, including subnuclei, were extracted automatically from structural scans in a cross-sectional cohort of VPT (n = 75) and full-term (FT, n = 41) aged 6-14 years. Group differences in amygdala volumes were assessed using ANCOVA, and associations with socio-emotional competencies were studied using partial least squares correlation (PLSC). In a VPT subgroup, additional longitudinal data with amygdala volumes at term-equivalent age (TEA) were manually extracted, growth rates calculated, and associations with school-age socio-emotional competencies investigated using PLSC.

RESULTS

Using cross-sectional data at school-age, amygdala volumes displayed comparable developmental patterns between the VPT and the FT groups. Greater volumes were associated with more emotional regulation difficulties in VPT and lower affect recognition competencies in FT. In the longitudinal VPT subgroup, no significant associations were found between amygdala volume trajectory and socio-emotional competencies.

CONCLUSION

Although our findings suggest typical amygdala development after VPT birth, further research is necessary to elucidate the developmental trajectory of amygdala and the role of resilience factors.

IMPACT

In our cohort, amygdala volumes, including subnuclei, displayed comparable developmental trajectories between the very preterm and the full-term groups. Higher amygdala volumes at school-age were associated with higher emotional regulation difficulties in the very-preterm born group, and with lower affect recognition abilities in full-term born children and adolescents. In a subgroup of very-preterm children and adolescents followed from birth to school-age, no significant associations were found between amygdala volumes at term-equivalent age and socio-emotional competencies at school-age.

Reading abilities in preterm children: a systematic review and meta-analysis

It is well recognized that children born preterm have specific learning difficulties. The objective of this study is to carry out a systematic review and meta-analysis on preterm children's reading ability performance. Of the 486 studies identified, 53 met the inclusion criteria, resulting in 143 effect sizes. 33,500 children between 5 and 18 years were included of whom 13,765 were preterm infants and 19,735 were full-term infants. Among preterm-born children without neurodevelopmental disorders significant differences and larger effect sizes were found in the reading subcategories, letter-word knowledge, reading comprehension, and spelling, whereas no significant differences were found in phonological awareness and rapid automatized naming. Extremely preterm children showed larger effect size. The present meta-analysis, which includes a much larger number of studies, shows that preterm children have lower performance than full-term children in reading and spelling. This fact underlines the need to design, develop and implement neuroeducational programs that take into account the characteristics of preterm born students.

Perinatal influences on academic achievement and the developing brain: a scoping systematic review

Introduction and methods

In this PRISMA-compliant systematic review, we identify and synthesize the findings of research in which neuroimaging and assessments of achievement have been used to examine the relationships among aspects of developmental programming, neurodevelopment, and achievement in reading and mathematics.

Results

Forty-seven studies met inclusion criteria. The majority examined the impact of prematurity (n = 32) and prenatal alcohol exposure (n = 13). Several prematurity studies reported a positive correlation between white-matter integrity of callosal fibers and executive functioning and/or achievement, and white matter properties were consistently associated with cognitive and academic performance in preterm and full-term children. Volumetric studies reported positive associations between academic and cognitive abilities and white and gray matter volume in regions such as the insula, putamen, and prefrontal lobes. Functional MRI studies demonstrated increased right-hemispheric language processing among preterm children. Altered activation of the frontoparietal network related to numerical abilities was also reported. Prenatal alcohol exposure studies reported alterations in white matter microstructure linked to deficits in cognitive functioning and academic achievement, including mathematics, reading, and vocabulary skills. Volumetric studies reported reductions in cerebral, cerebellar, and subcortical gray matter volumes associated with decreased scores on measures of executive functioning, attention, working memory, and academic performance. Functional MRI studies demonstrated broad, diffuse activation, reduced activation in canonical regions, and increased activation in non-canonical regions during numeric tasks.

Discussion

A preponderance of studies linked prematurity and prenatal alcohol exposure to altered neurodevelopmental processes and suboptimal academic achievement. Limitations and recommendations for future research are discussed.

Systematic review registration

Identifier: DOI 10.17605/OSF.IO/ZAN67.

Meta-Analysis of Hippocampal Volume and Episodic Memory in Preterm and Term Born Individuals

Preterm birth (< 37 weeks gestation) has been associated with memory deficits, which has prompted investigation of possible alterations in hippocampal volume in this population. However, existing literature reports varying effects of premature birth on hippocampal volume. Specifically, it is unclear whether smaller hippocampal volume in preterm-born individuals is merely reflective of smaller total brain volume. Further, it is not clear if hippocampal volume is associated with episodic memory functioning in preterm-born individuals. Meta-analysis was used to investigate the effects of premature birth on hippocampal volume and episodic memory from early development to young adulthood (birth to 26). PubMed, PsychINFO, and Web of Science were searched for English peer-reviewed articles that included hippocampal volume of preterm and term-born individuals. Thirty articles met the inclusion criteria. Separate meta-analyses were used to evaluate standardized mean differences between preterm and term-born individuals in uncorrected and corrected hippocampal volume, as well as verbal and visual episodic memory. Both uncorrected and corrected hippocampal volume were smaller in preterm-born compared to term-born individuals. Although preterm-born individuals had lower episodic memory performance than term-born individuals, the limited number of studies only permitted a qualitative review of the association between episodic memory performance and hippocampal volume. Tested moderators included mean age, pre/post-surfactant era, birth weight, gestational age, demarcation method, magnet strength, and slice thickness. With this meta-analysis, we provide novel evidence of the effects of premature birth on hippocampal volume.

Perinatal compromise affects development, form, and function of the hippocampus part one; clinical studies

The hippocampus is a neuron-rich specialised brain structure that plays a central role in the regulation of emotions, learning and memory, cognition, spatial navigation, and motivational processes. In human fetal development, hippocampal neurogenesis is principally complete by mid-gestation, with subsequent maturation comprising dendritogenesis and synaptogenesis in the third trimester of pregnancy and infancy. Dendritogenesis and synaptogenesis underpin connectivity. Hippocampal development is exquisitely sensitive to perturbations during pregnancy and at birth. Clinical investigations demonstrate that preterm birth, fetal growth restriction (FGR), and acute hypoxic-ischaemic encephalopathy (HIE) are common perinatal complications that alter hippocampal development. In turn, deficits in hippocampal development and structure mediate a range of neurodevelopmental disorders, including cognitive and learning problems, autism, and Attention-Deficit/Hyperactivity Disorder (ADHD). In this review, we summarise the developmental profile of the hippocampus during fetal and neonatal life and examine the hippocampal deficits observed following common human pregnancy complications. IMPACT: The review provides a comprehensive summary of the developmental profile of the hippocampus in normal fetal and neonatal life. We address a significant knowledge gap in paediatric research by providing a comprehensive summary of the relationship between pregnancy complications and subsequent hippocampal damage, shedding new light on this critical aspect of early neurodevelopment.

Novel metrics to characterize temporal lobe of very preterm infants on term-equivalent brain MRI

BACKGROUND

Preterm birth adversely impacts brain development and contributes to neurodevelopmental impairment; the temporal lobe may be particularly vulnerable to the impact of very preterm (VP) birth. Yet, no prior magnetic resonance imaging (MRI) scoring system incorporated a method to quantify temporal lobe size in VP infants.

METHODS

We developed and applied three metrics (temporal lobe length, extra-axial space, and temporal horn width) to quantify temporal lobe structure on term-equivalent brain MRIs obtained from 74 VP and 16 term infants. We compared metrics between VP and term infants and explored associations of each metric with perinatal risk factors.

RESULTS

All metrics had excellent reliability (intra-class correlation coefficient 0.62-0.98). VP infants had lower mean temporal lobe length (76.8 mm versus 79.2 mm, p = 0.02); however, the difference attenuated after correction for postmenstrual age. VP infants had larger temporal horn widths compared with term infants (2.6 mm versus 1.8 mm, p < 0.001). Temporal lobe length was positively associated with gestational age, birth weight, and male sex, and negatively associated with the duration of parenteral nutrition.

CONCLUSIONS

The proposed metrics are reliable and sensitive in distinguishing differences in temporal lobe development between VP and full-term infants.

IMPACT

We developed a novel method for quantifying temporal lobe size among very preterm infants at term equivalent using simple metrics performed on brain MRI. Temporal lobe metrics were reliable, correlated with brain volume from volumetric analysis, and were sensitive in identifying differences in temporal lobe development among preterm compared with term infants, specifically larger temporal horn size in preterm infants. This temporal lobe metric system will enable future work to delineate the perinatal and postnatal factors that impact temporal lobe growth, and better understand the relationship between temporal lobe disturbance and neurodevelopment in very preterm infants.

Effect of Extremely Preterm Birth on Adolescent Brain Network Organization

Introduction: Extremely preterm (EPT) birth, defined as birth at a gestational age (GA) <28 weeks, can have a lasting impact on cognition throughout the life span. Previous investigations reveal differences in brain structure and connectivity between infants born preterm and full-term (FT), but how does preterm birth impact the adolescent connectome? Methods: In this study, we investigate how EPT birth can alter broadscale network organization later in life by comparing resting-state functional magnetic resonance imaging connectome-based parcellations of the entire cortex in adolescents born EPT (N = 22) to age-matched adolescents born FT (GA ≥37 weeks, N = 28). We compare these parcellations to adult parcellations from previous studies and explore the relationship between an individual's network organization and behavior. Results: Primary (occipital and sensorimotor) and frontoparietal networks were observed in both groups. However, there existed notable differences in the limbic and insular networks. Surprisingly, the connectivity profile of the limbic network of EPT adolescents was more adultlike than the same network in FT adolescents. Finally, we found a relationship between adolescents' overall cognition score and their limbic network maturity. Discussion: Overall, preterm birth may contribute to the atypical development of broadscale network organization in adolescence and may partially explain the observed cognitive deficits.

Pathways link environmental and genetic factors with structural brain networks and psychopathology in youth

Adolescence is a period of significant brain development and maturation, and it is a time when many mental health problems first emerge. This study aimed to explore a comprehensive map that describes possible pathways from genetic and environmental risks to structural brain organization and psychopathology in adolescents. We included 32 environmental items on developmental adversity, maternal substance use, parental psychopathology, socioeconomic status (SES), school and family environment; 10 child psychopathological scales; polygenic risk scores (PRS) for 10 psychiatric disorders, total problems, and cognitive ability; and structural brain networks in the Adolescent Brain Cognitive Development study (ABCD, n = 9168). Structural equation modeling found two pathways linking SES, brain, and psychopathology. Lower SES was found to be associated with lower structural connectivity in the posterior default mode network and greater salience structural connectivity, and with more severe psychosis and internalizing in youth (p < 0.001). Prematurity and birth weight were associated with early-developed sensorimotor and subcortical networks (p < 0.001). Increased parental psychopathology, decreased SES and school engagement was related to elevated family conflict, psychosis, and externalizing behaviors in youth (p < 0.001). Increased maternal substance use predicted increased developmental adversity, internalizing, and psychosis (p < 0.001). But, polygenic risks for psychiatric disorders had moderate effects on brain structural connectivity and psychopathology in youth. These findings suggest that a range of genetic and environmental factors can influence brain structural organization and psychopathology during adolescence, and that addressing these risk factors may be important for promoting positive mental health outcomes in young people.

Long-lasting effects of very preterm birth on brain structure in adulthood: A systematic review and meta-analysis

Early life experiences, such as very preterm (VP) birth, can affect brain and cognitive development. Several prior studies investigated brain structure in adults born VP; synthesising these studies may help to provide a clearer understanding of long-term effects of VP birth on the brain. We systematically searched Medline and Embase for articles that investigated brain structure using MRI in adulthood in individuals born VP (<32 weeks' gestation) or with very low birth weight (VLBW; <1500 g), and controls born at term or with normal birth weight. In total, 77 studies met the review inclusion criteria, of which 28 studies were eligible for meta-analyses, including data from up to 797 VP/VLBW participants and 518 controls, aged 18-33 years. VP/VLBW adults exhibited volumetric, morphologic and microstructural alterations in subcortical and temporal cortical regions compared with controls, with pooled standardised mean differences up to - 1.0 (95% confidence interval: -1.2, -0.8). This study suggests there is a persisting neurological impact of VP birth, which may provide developmental neurobiological insights for adult cognition in high-risk populations.

Intellectual functioning in survivors of extremely low birthweight: Cognitive outcomes in childhood and adolescence

BACKGROUND

Infants born at extremely low birthweight (ELBW: ≤1000 g) are vulnerable to intellectual disabilities, but the factors that may distinguish between ELBW survivors with and without these impairments are not well understood. In this study, prospective associations between neonatal factors and functional outcomes in childhood and adolescence were compared in ELBW survivors with and without borderline intellectual functioning (BIF).

METHODS

Borderline intellectual functioning was defined by IQ < 85, assessed at 8 years. Among 146 ELBW survivors, 48 (33%) had IQ scores under 85, and 98 (67%) had scores equal to or over 85. Group differences in demographic and risk factors were assessed via t-test, chi-squared analysis or non-parametric tests. Neonatal factors that differed between ELBW groups were tested for association with adaptive behaviour assessed at age 5 years, and reading and arithmetic skills assessed at ages 8 and 15 years, using hierarchical regression models.

RESULTS

Extremely low birthweight survivors with BIF had significantly lower birthweights than ELBW survivors without BIF (790 vs. 855 g, P < 0.01) and were more likely to be born to mothers with lower socioeconomic status (SES) (78% vs. 48%, P < 0.01). These ELBW survivors also were more likely to be diagnosed with significant neurosensory impairment (NSI; 35% vs. 19%, P < 0.04), experienced more bronchopulmonary dysplasia (56% vs. 38%, P < 0.04), received more days of respiratory support (median 33 vs. 14 days, P < 0.01) and remained in hospital for longer periods (median 81 vs. 63 days, P < 0.03). Birthweight, familial SES, NSI and duration of respiratory support were significant predictors for one or more outcomes. Across groups, lower familial SES was associated with lower academic scores (Ps < 0.05), and NSI predicted lower adaptive functioning (Ps < 0.001). Other associations were moderated by group: among ELBW survivors with BIF, heavier birthweights predicted better arithmetic skills, the presence of NSI was associated with poorer arithmetic skills and more ventilation days predicted poorer reading skills.

CONCLUSIONS

At birth, ELBW survivors with BIF faced more physiological and social disadvantages and required more medical intervention than their ELBW peers without BIF. Smaller birth size, NSI burden and prolonged neonatal ventilatory support displayed gradients of risk for childhood and adolescent academic outcomes across groups. Whereas academic performance in ELBW survivors with BIF was sensitive to variation in birth size, NSI or ventilation days, ELBW survivors without BIF attained thresholds of intellectual ability that were sufficient to support higher levels of academic performance at both ages, regardless of their status on these factors. The findings are discussed in relation to Zigler's developmental theory of intellectual disability.

Episodic and prospective memory difficulties in 13-year-old children born very preterm

OBJECTIVES

Children born very preterm (VP) are susceptible to a range of cognitive impairments, yet the effects of VP birth on long-term, episodic, and prospective memory remains unclear. This study examined episodic and prospective memory functioning in children born VP compared with their term-born counterparts at 13 years.

METHOD

VP (n = 81: born <30 weeks' gestation) and term (n = 26) groups were aged between 12 and 14 years. Children completed: (i) standardized verbal and visuospatial episodic memory tests; and (ii) an experimental time- and event-based prospective memory test that included short-term (within assessment session) and long-term (up to 1-week post-session) tasks. Parents completed a questionnaire assessing memory functions in everyday life.

RESULTS

The VP group performed worse on all measures of verbal and visuospatial episodic memory than the term group. While there were no group differences in event-based or long-term prospective memory, the VP group performed worse on time-based and short-term prospective memory tasks than term-born counterparts. Parents of children born VP reported more everyday memory difficulties than parents of children born at term, with parent-ratings indicating significantly elevated rates of everyday memory challenges in children born VP.

CONCLUSIONS

Children born VP warrant long-term surveillance, as challenges associated with VP birth include memory difficulties at 13 years. This study highlights the need for greater research and clinical attention into childhood functional memory outcomes.

Differentiate preterm and term infant brains and characterize the corresponding biomarkers via DICCCOL-based multi-modality graph neural networks

Preterm birth is a worldwide problem that affects infants throughout their lives significantly. Therefore, differentiating brain disorders, and further identifying and characterizing the corresponding biomarkers are key issues to investigate the effects of preterm birth, which facilitates the interventions for neuroprotection and improves outcomes of prematurity. Until now, many efforts have been made to study the effects of preterm birth; however, most of the studies merely focus on either functional or structural perspective. In addition, an effective framework not only jointly studies the brain function and structure at a group-level, but also retains the individual differences among the subjects. In this study, a novel dense individualized and common connectivity-based cortical landmarks (DICCCOL)-based multi-modality graph neural networks (DM-GNN) framework is proposed to differentiate preterm and term infant brains and characterize the corresponding biomarkers. This framework adopts the DICCCOL system as the initialized graph node of GNN for each subject, utilizing both functional and structural profiles and effectively retaining the individual differences. To be specific, functional magnetic resonance imaging (fMRI) of the brain provides the features for the graph nodes, and brain fiber connectivity is utilized as the structural representation of the graph edges. Self-attention graph pooling (SAGPOOL)-based GNN is then applied to jointly study the function and structure of the brain and identify the biomarkers. Our results successfully demonstrate that the proposed framework can effectively differentiate the preterm and term infant brains. Furthermore, the self-attention-based mechanism can accurately calculate the attention score and recognize the most significant biomarkers. In this study, not only 87.6% classification accuracy is observed for the developing Human Connectome Project (dHCP) dataset, but also distinguishing features are explored and extracted. Our study provides a novel and uniform framework to differentiate brain disorders and characterize the corresponding biomarkers.

Assessment of brain two-dimensional metrics in infants born preterm at term equivalent age: Correlation of ultrasound scans with magnetic resonance imaging

CONTEXT

Developing brain imaging is a critical subject for infants born preterm. Impaired brain growth is correlated with poor neurological outcomes, regardless of overt brain lesions, such as hemorrhage or leukomalacia. As magnetic resonance imaging (MRI) remains a research tool for assessing regional brain volumes, two-dimensional metrics (2D metrics) provide a reliable estimation of brain structures. In neonatal intensive care, cerebral ultrasound (cUS) is routinely performed to assess brain integrity. This prospective work has compared US and MRI accuracy for the measurement of 2D brain metrics and identification of overt injuries.

METHODS

MRI and cUS were performed at term equivalent age (TEA) in infants born before 32 weeks of gestation (GW). Demographical data and results of serial cUS (Neonatal Intensive Care Unit [NICU]-US) performed during hospitalization were gathered from medical charts. Blinded, experienced senior doctors reviewed the scans for both standard analysis and standardized, 2D measurements. The correlation of 2D metrics and inter-/intraobserver agreements were evaluated using Pearson's coefficient, Bland-Altman plots, and intraclass coefficient (ICC), respectively.

RESULTS

In total, 102 infants born preterm were included. The performance of "TEA-cUS and NICU-cUS" when compared to "TEA-MRI and NICU-cUS" was identical for the detection of high-grade hemorrhages and close for low-grade ones. However, TEA-MRI only detected nodular lesions of the white matter (WM). No infant presented a cerebellar infarct on imaging. Intra- and inter-observer agreements were excellent for all 2D metrics except for the corpus callosum width (CCW) and anteroposterior vermis diameter. MRI and cUS showed good to excellent correlation for brain and bones biparietal diameters, corpus callosum length (CCL), transcerebellar diameters (TCDs), and lateral ventricle diameters. Measures of CCW and vermis dimensions were poorly correlated.

CONCLUSION AND PERSPECTIVE

The cUS is a reliable tool to assess selected 2D measurements in the developing brain. Repetition of these metrics by serial cUS during NICU stay would allow the completion of growth charts for several brain structures. Further studies will assess whether these charts are relevant markers of neurological outcome.

Exploring the distribution of grey and white matter brain volumes in extremely preterm children, using magnetic resonance imaging at term age and at 10 years of age

OBJECTIVES

To investigate differences in brain volumes between children born extremely preterm and term born controls at term age and at 10 years of age.

STUDY DESIGN

Children born extremely preterm (EPT), up to 26 weeks and 6 days gestational age, in Stockholm between January 1 2004 to March 31 2007 were included in this population-based cohort study. A total of 45 EPT infants were included at term age and 51 EPT children were included at 10 years of age. There were 27 EPT children included at both time points. Two different control groups were recruited; 15 control infants were included at term age and 38 control children at 10 years of age. The primary outcomes were the grey and white matter volumes. Linear regression, adjusted for intracranial volume and sex, was used.

RESULTS

At term age, the extremely preterm infants had significantly smaller grey matter volume compared to the control infants with an adjusted mean difference of 5.0 cm3 and a 95% confidence interval of -8.4 to -1.5 (p = 0.004). At 10 years of age the extremely preterm children had significantly smaller white matter volume compared to the control children with an adjusted mean difference of 6.0 cm3 and a 95% confidence interval of -10.9 to -1.0 (p = 0.010).

CONCLUSION

Extremely preterm birth was associated with reduced grey matter volume at term age and reduced white matter volume at 10 years of age compared to term born controls.

Growth and Development in Preterm Infants: What is The Long-Term Risk?

ABSTRACT Background: Indonesia comes in the fifth for the greatest number of preterm births. Preterm infants may inflict various complication as the result of underdeveloped immunity, affecting their growth and development in the long run until they reach adult phase. Such complications could be prevented through adequate nutrition fulfillment. Purpose: This article aimed to elaborate the characteristics of growth and development of premature babies, long term effect on the development and the impact of immunity and gut health of preterm infants in supporting their growth and development. Methods: References cited in this article were obtained from the latest primary literature within the last 10 years. Discussion: The rate and ability of infants to perform catch-up growth depends on the birth weight and gestation age, at which the lower birth weight and lower gestational age had slower rate. Brain structures that of preterm infants differ compared to the term, and these changes give rise to various clinical outcomes, including long term emotional, behavioral changes, cognitive and executive functioning. Immature immune system in preterm infants reduces the protective ability by innate and adaptive immunity in overcoming pathogens compared to term infants, including gut microbiota prematurity which affects nutrition absorption and growth and development catch up ability. Appropriate and adequate nutrition supplementation has shown beneficial effects in promoting the growth of normal gut flora, which allow better absorption of nutrition and therefore enhancing growth rate and supporting the development of preterm infants. Conclusions: Optimal growth and development of preterm infants are supported by sufficient nutrition supplementation to support the growth of gut microbiota, facilitating the catch-up growth and development of premature infants and immune system maturity.

Bone health in young adult survivors born extremely preterm or extremely low birthweight in the post surfactant era

BACKGROUND

Most infants born extremely preterm (EP; <28 weeks' gestation) or extremely low birthweight (ELBW; <1000 g birthweight) in the post surfactant era (early 1990s) are now surviving into adulthood. Preterm birth/low birthweight are risk factors for reduced bone growth and mineralisation in infants and children. However, little is known about their bone health around peak bone mass and through adult life.

OBJECTIVE

To compare bone health (bone mineral measures, bone structure and strength) in young adults born EP/ELBW with controls (>2499 g birthweight), and within the EP/ELBW group examine perinatal and later variables associated with long term bone health.

METHODS

A geographic cohort comprising all 297 survivors born EP/ELBW in 1991-92 in the state of Victoria, Australia, and 260 contemporaneous controls (>2499 g birthweight) were recruited into a longitudinal study from birth. At age 25 years, investigations included dual energy X ray absorptiometry and peripheral quantitative computed tomography to measure bone, muscle and soft tissue variables, and fasting blood samples to measure serum 25 hydroxyvitamin D (25(OH)D) and bone turnover markers (BTM). Linear regression analysis, with models fitted using generalised estimating equations, was used to compare outcomes between groups, adjusting for height and weight.

RESULTS

Compared with controls (n = 129), young adults born EP/ELBW (n = 162) had lower areal bone mineral density (g/cm²) (mean difference [MD] -0.044; 95% confidence interval [CI] -0.076,-0.013) and Z-scores (MD -0.53; 95% CI -0.75, -0.30) in the femoral neck, and lower total hip Z-score (MD -0.35; 95% CI -0.54, -0.15) after adjusting for height and weight. EP/ELBW males generally displayed more bone and soft tissue deficits than females, compared with their respective controls. Within the EP/ELBW group, early growth, male sex, height and lean mass, muscle measures, 25(OH)D levels, and BTM were independently associated with bone mineral measures, structure or strength.

CONCLUSIONS

Young adults born EP/ELBW had evidence of impaired bone health around the age of peak bone mass compared with controls. Further follow-up of the EP/ELBW groups will determine if they have a heightened low-trauma fracture risk in later life.

Reference Charts for Neonatal Cranial Volume Based on 3D Laser Scanning to Monitor Head Growth

Background: Postnatal brain growth is an important predictor of neurodevelopmental outcome in preterm infants. A new reliable proxy for brain volume is cranial volume, which can be measured routinely by 3-D laser scanning. The aim of this study was to develop reference charts for normal cranial volume in newborn infants at different gestational ages starting from late preterm for both sexes. Methods: Cross-sectional cohort study in a German university hospital, including singleton, clinically stable, neonates born after 34 weeks of gestation. Cranial volume was measured in the first week of life by a validated 3-D laser scanner. Cranial volume data was modeled to calculate percentile values by gestational age and birth weight and to develop cranial volume reference charts for girls and boys separately. Results: Of the 1,703 included infants, 846 (50%) were female. Birth weights ranged from 1,370 to 4,830 grams (median 3,370). Median cranial volume ranged from 320 [interquartile range (IQR) 294-347] ml at 34 weeks to 469 [IQR 442-496] ml at 42 weeks and was higher in boys than in girls. Conclusions: This study presents the first reference charts of cranial volume which can be used in clinical practice to monitor brain growth between 34 and 42 weeks gestation in infants.

Perinatal and childhood predictors of general cognitive outcome at 28 years in a very-low-birthweight national cohort

AIM

To determine IQ at 26 to 30 years in very-low-birthweight (VLBW) adults compared with term-born controls; and to examine the stability of IQ in VLBW individuals between 7 to 8 years and 26 to 30 years, identify perinatal and social predictors of IQ, and assess the contribution of brain volume to IQ.

METHOD

At 26 to 30 years, 229 VLBW adults (71% survivors of prospectively enrolled national cohort) and 100 term-born controls were tested on the Wechsler Abbreviated Scale of Intelligence. For VLBW, IQ at 7 to 8 years, perinatal and social data were extracted from the data set, and 150 adults underwent volumetric cranial magnetic resonance imaging (MRI).

RESULTS

At 26 to 30 years, the mean adjusted difference between VLBW and controls for total IQ was 9.4 (95% CI 6.5-12.4) points. In VLBW individuals the correlation between IQ scores at 7 to 8 years and 26 to 30 years was 0.78. On multiple regression analysis, parental education was the strongest predictor of verbal and total IQ at both ages. Birthweight was a strong predictor of perceptual and total IQ. In VLBW individuals with MRI scans, the addition of brain volume as a variable increased the variance explained for perceptual and total IQ.

INTERPRETATION

VLBW adults have mean IQ scores 9 to 11 points below controls. Parental education and birthweight are the strongest predictors of IQ.

Gestational Age is Dimensionally Associated with Structural Brain Network Abnormalities Across Development

Prematurity is associated with diverse developmental abnormalities, yet few studies relate cognitive and neurostructural deficits to a dimensional measure of prematurity. Leveraging a large sample of children, adolescents, and young adults (age 8-22 years) studied as part of the Philadelphia Neurodevelopmental Cohort, we examined how variation in gestational age impacted cognition and brain structure later in development. Participants included 72 preterm youth born before 37 weeks' gestation and 206 youth who were born at term (37 weeks or later). Using a previously-validated factor analysis, cognitive performance was assessed in three domains: (1) executive function and complex reasoning, (2) social cognition, and (3) episodic memory. All participants completed T1-weighted neuroimaging at 3 T to measure brain volume. Structural covariance networks were delineated using non-negative matrix factorization, an advanced multivariate analysis technique. Lower gestational age was associated with both deficits in executive function and reduced volume within 11 of 26 structural covariance networks, which included orbitofrontal, temporal, and parietal cortices as well as subcortical regions including the hippocampus. Notably, the relationship between lower gestational age and executive dysfunction was accounted for in part by structural network deficits. Together, these findings emphasize the durable impact of prematurity on cognition and brain structure, which persists across development.

Early childhood deprivation is associated with alterations in adult brain structure despite subsequent environmental enrichment

Millions of children worldwide live in nonfamilial institutions. We studied impact on adult brain structure of a particularly severe but time-limited form of institutional deprivation in early life experienced by children who were subsequently adopted into nurturing families. Institutional deprivation was associated with lower total brain volume in a dose-dependent way. Regionally specific effects were seen in medial prefrontal, inferior frontal, and inferior temporal areas. Deprivation-related alterations in total brain volume were associated with lower intelligence quotient and more attention deficit/hyperactivity disorder symptoms; alterations in temporal volume seemed compensatory, as they were associated with fewer attention deficit/hyperactivity disorder symptoms. We provide evidence that early childhood deprivation is related to alterations in adult brain structure, despite environmental enrichment in intervening years.

Early childhood deprivation is associated with higher rates of neurodevelopmental and mental disorders in adulthood. The impact of childhood deprivation on the adult brain and the extent to which structural changes underpin these effects are currently unknown. To investigate these questions, we utilized MRI data collected from young adults who were exposed to severe deprivation in early childhood in the Romanian orphanages of the Ceaușescu era and then, subsequently adopted by UK families; 67 Romanian adoptees (with between 3 and 41 mo of deprivation) were compared with 21 nondeprived UK adoptees. Romanian adoptees had substantially smaller total brain volumes (TBVs) than nondeprived adoptees (8.6% reduction), and TBV was strongly negatively associated with deprivation duration. This effect persisted after covarying for potential environmental and genetic confounds. In whole-brain analyses, deprived adoptees showed lower right inferior frontal surface area and volume but greater right inferior temporal lobe thickness, surface area, and volume than the nondeprived adoptees. Right medial prefrontal volume and surface area were positively associated with deprivation duration. No deprivation-related effects were observed in limbic regions. Global reductions in TBV statistically mediated the observed relationship between institutionalization and both lower intelligence quotient (IQ) and higher levels of attention deficit/hyperactivity disorder symptoms. The deprivation-related increase in right inferior temporal volume seemed to be compensatory, as it was associated with lower levels of attention deficit/hyperactivity disorder symptoms. We provide compelling evidence that time-limited severe deprivation in the first years of life is related to alterations in adult brain structure, despite extended enrichment in adoptive homes in the intervening years.

Tracking regional brain growth up to age 13 in children born term and very preterm

Serial regional brain growth from the newborn period to adolescence has not been described. Here, we measured regional brain growth in 216 very preterm (VP) and 45 full-term (FT) children. Brain MRI was performed at term-equivalent age, 7 and 13 years in 82 regions. Brain volumes increased between term-equivalent and 7 years, with faster growth in the FT than VP group. Perinatal brain abnormality was associated with less increase in brain volume between term-equivalent and 7 years in the VP group. Between 7 and 13 years, volumes were relatively stable, with some subcortical and cortical regions increasing while others reduced. Notably, VP infants continued to lag, with overall brain size generally less than that of FT peers at 13 years. Parieto–frontal growth, mainly between 7 and 13 years in FT children, was associated with higher intelligence at 13 years. This study improves understanding of typical and atypical regional brain growth.

In this longitudinal study, the authors tracked the course of brain development from birth to adolescence (age 13 years) and examined the effects of very preterm birth. Very preterm children showed slower brain growth from age 0 (term equivalent) to age 7.

Rewiring the extremely preterm brain: Altered structural connectivity relates to language function

Children born preterm are at increased risk for cognitive impairment, with higher-order functions such as language being especially vulnerable. Previously, we and others have reported increased interhemispheric functional connectivity in children born extremely preterm; the finding appears at odds with literature showing decreased integrity of the corpus callosum, the primary commissural bundle, in preterm children. We address the apparent discrepancy by obtaining advanced measures of structural connectivity in twelve school-aged children born extremely preterm (<28 weeks) and ten term controls. We hypothesize increased extracallosal structural connectivity might support the functional hyperconnectivity we had previously observed. Participants were aged four to six years at time of study and groups did not differ in age, sex, race, ethnicity, or socioeconomic status. Whole-brain and language-network-specific (functionally-constrained) connectometry analyses were performed. At the whole-brain level, preterm children had decreased connectivity in the corpus callosum and increased connectivity in the cerebellum versus controls. Functionally-constrained analyses revealed significantly increased extracallosal connectivity between bilateral temporal regions in preterm children (FDRq <0.05). Connectivity within these extracallosal pathways was positively correlated with performance on standardized language assessments in children born preterm (FDRq <0.001), but unrelated to performance in controls. This is the first study to identify anatomical substrates for increased interhemispheric functional connectivity in children born preterm; increased reliance on an extracallosal pathway may represent a biomarker for resiliency following extremely preterm birth.

High Blood Pressure in Young Adult Survivors Born Extremely Preterm or Extremely Low Birthweight in the Post Surfactant Era

More infants born extremely preterm (<28 weeks’ gestation) or extremely low birthweight (<1000 g) are surviving into adulthood in recent years. Preterm adolescents have higher blood pressure (BP) than normal birthweight controls, but how their BP changes with increasing age is not known. We compared BP at 25 years and trajectories of BP (change per year) from 18 to 25 years between survivors born <28 weeks/<1000 g and normal birthweight (>2499 g) controls born in the early 1990s, when survival rates began to rise. Participants were derived from 297 consecutive survivors born <28 weeks/<1000 g in 1991 to 1992 in Victoria, Australia, and 260 contemporaneous controls. At age 25 years, ambulatory BP was measured in 151 and 119 participants, respectively. Participants born <28 weeks/<1000 g had higher 24-hour systolic (mean difference 4.5 [95% CI, 1.2–7.7 mm Hg]), diastolic (3.4 [1.5–5.2 mm Hg]), and mean BPs (3.6 [1.4–5.8 mm Hg]) compared with the controls. Similar patterns were observed for both awake and asleep periods. Asleep ambulatory BP between 18 and 25 years increased more in participants born <28 weeks/<1000 g than in controls (systolic 0.56, diastolic 0.41, and mean 0.41 mm Hg increase per year; all P <0.05). Young adults born <28 weeks/<1000 g in the post surfactant era have higher BP and an increased trajectory of ambulatory BP compared with controls. With more survivors born <28 weeks/<1000 g now reaching adulthood, these findings are important for early detection and timely management of hypertension in this high-risk population.

Disrupted Visual Cortex Neurophysiology Following Very Preterm Birth

BACKGROUND

Visual regions develop rapidly in utero and throughout early childhood, but very preterm (VPT) birth can disrupt the typical maturation of primary cortices, with VPT children exhibiting mild visual impairments in early life and throughout development. This is thought to be due to dysfunctional maturation of occipital cortices. A way to readily index brain function is to examine neural oscillations; these mechanisms play a central role in the modeling and pruning of connections, providing an intrinsic temporal structure that refines the precise alignment of spiking, processing information in the brain, and coordinating networks.

METHODS

Using magnetoencephalography, we examined regional oscillatory patterns and functional coupling in VPT and full-term children. Five minutes of eyes-open resting-state data were acquired from 27 VPT and 32 full-term children at 8 years of age.

RESULTS

As hypothesized, the VPT group, when compared with control children, had elevated theta-band power, while alpha amplitude envelope coupling, a marker of connectivity, was found to be decreased.

CONCLUSIONS

These results support the hypothesis of spectral slowing in VPT children and more broadly suggest that the developmental arc of visual neurophysiology is disrupted by VPT birth. We conclude that these deficits underlie difficulties in complex visual perceptual processing evident during childhood and beyond.

Associations of Growth and Body Composition with Brain Size in Preterm Infants

OBJECTIVE

To assess the association of very preterm infants' brain size at term-equivalent age with physical growth from birth to term and body composition at term.

STUDY DESIGN

We studied 62 infants born at <33 weeks of gestation. At birth and term, we measured weight and length and calculated body mass index. At term, infants underwent air displacement plethysmography to determine body composition (fat and fat-free mass) and magnetic resonance imaging to quantify brain size (bifrontal diameter, biparietal diameter, transverse cerebellar distance). We estimated associations of physical growth (Z-score change from birth to term) and body composition with brain size, adjusting for potential confounders using generalized estimating equations.

RESULTS

The median gestational age was 29 weeks (range, 24.0-32.9 weeks). Positive gains in weight and body mass index Z-score were associated with increased brain size. Each additional 100 g of fat-free mass at term was associated with larger bifrontal diameter (0.6 mm; 95% CI, 0.2-1.0 mm), biparietal diameter (0.7 mm; 95% CI, 0.3-1.1 mm), and transverse cerebellar distance (0.3 mm; 95% CI, 0.003-0.5 mm). Associations between fat mass and brain metrics were not statistically significant.

CONCLUSIONS

Weight and body mass index gain from birth to term, and lean mass-but not fat-at term, were associated with larger brain size. Factors that promote lean mass accrual among preterm infants may also promote brain growth.

Quantitative MRI study of infant regional brain size following surgery for long-gap esophageal atresia requiring prolonged critical care

INTRODUCTION

Little is known regarding the impact of concurrent critical illness and thoracic noncardiac perioperative critical care on postnatal brain development. Previously, we reported smaller total brain volumes in both critically ill full-term and premature patients following complex perioperative critical care for long-gap esophageal atresia (LGEA). Our current report assessed trends in regional brain sizes during infancy, and probed for any group differences.

METHODS

Full-term (n = 13) and preterm (n = 13) patients without any previously known neurological concerns, and control infants (n = 16), underwent non-sedated 3 T MRI in infancy (<1 year old). T2-weighted images underwent semi-automated brain segmentation using Morphologically Adaptive Neonatal Tissue Segmentation (MANTiS). Regional tissue volumes of the forebrain, deep gray matter (DGM), cerebellum, and brainstem are presented as absolute (cm3) and normalized (% total brain volume (%TBV)) values. Group differences were assessed using a general linear model univariate analysis with corrected age at scan as a covariate.

RESULTS

Absolute volumes of regions analyzed increased with advancing age, paralleling total brain size, but were significantly smaller in both full-term and premature patients compared to controls. Normalized volumes (%TBV) of forebrain, DGM, and cerebellum were not different between subject groups analyzed. Normalized brainstem volumes showed group differences that warrant future studies to confirm the same finding.

DISCUSSION

Both full-term and premature critically ill infants undergoing life-saving surgery for LGEA are at risk of smaller total and regional brain sizes. Normalized volumes support globally delayed or diminished brain growth in patients. Future research should look into neurodevelopmental outcomes of infants born with LGEA.

Educational and health outcomes associated with bronchopulmonary dysplasia in 15-year-olds born preterm

Introduction

To evaluate the consequences of bronchopulmonary dysplasia (BPD) on academic outcomes and healthcare use in adolescents born very preterm.

Methods

This cohort study included 15-year-old adolescents born very preterm (< 32 weeks) between 2011 and 2013, with and without BPD, and controls born full term. Data regarding academic performance, current medical follow-up, and family characteristics were collected. Multivariate logistic regression was used to quantify relationships between academic outcomes and BPD.

Results

From the 1341 children included in the initial cohort, 985 adolescents were eligible and 351 included (55 preterms with a history of BPD, 249 without, and 47 controls). Among adolescents born very preterm, a history of BPD was associated with a higher risk to attend a school for children with special needs (p < 0.05) and to have repeated a grade (p = 0.01). It was also associated with an increased number of medical and paramedical consultations. A history of BPD was not associated with the parents’ employment status, family structure, or the presence of younger siblings.

Conclusion

This study highlights that a history of BPD is associated with poorer academic outcomes and high healthcare use in adolescence.

Impact of extreme prematurity or extreme low birth weight on young adult health and well-being: the Victorian Infant Collaborative Study (VICS) 1991-1992 Longitudinal Cohort study protocol

INTRODUCTION

Infants born extremely preterm (EP, <28 weeks' gestation) or with extremely low birth weight (ELBW,<1000 g) in the era when surfactant has been available clinically are at high risk of health and developmental problems in childhood and adolescence. However, how their health and well-being may be affected in adulthood is not well known. This study aims to compare between EP/ELBW and normal birthweight (NBW) controls: (1) physical health, mental health and socioemotional functioning at 25 years of age and (2) trajectories of these outcomes from childhood to adulthood. In addition, this study aims to identify risk factors in pregnancy, infancy, childhood and adolescence for poor physical health and well-being in EP/ELBW young adults.

METHODS AND ANALYSIS

The Victorian Infant Collaborative Study (VICS) is a prospective geographical cohort of all EP/ELBW survivors to 18 years of age born in the State of Victoria, Australia, from 1 January 1991 to 31 December 1992 (n=297) and contemporaneous term-born/NBW controls (n=262). Participants were recruited at birth and followed up at 2, 5, 8 and 18 years. This 25-year follow-up includes assessments of physical health (cardiovascular, respiratory and musculoskeletal), mental health and socioemotional functioning. Outcomes will be compared between the birth groups using linear and logistic regression, fitted using generalised estimating equations (GEEs). Trajectories of health outcomes from early childhood will be compared between the birth groups using linear mixed-effects models. Risk factors for adult outcomes will be assessed using linear and logistic regression (fitted using GEEs).

ETHICS AND DISSEMINATION

This study was approved by the Human Research Ethics Committees of the Royal Women's Hospital, Mercy Hospital for Women, Monash Medical Centre and the Royal Children's Hospital, Melbourne. Study outcomes will be disseminated through conference presentations, peer-reviewed publications, the internet and social media.

Non-invasive estimation of brain-volume in infants

BACKGROUND

Neurological development is determined by brain growth. Methods to measure total brain volume (TBV) in clinical settings are limited. MR-imaging represents the gold-standard.

AIMS

The present study tests the hypotheses that in infants without any brain pathology, TBV - as determined by MRI - can be accurately estimated by cranial volume (CrV), measured by 3D-laser scanning. In case of good correlation of CrV with TBV it was further tested, whether CrV can be also estimated by (I) head circumference (HC) or (II) by other technology than laser scanning.

STUDY DESIGN & SUBJECTS

To test the hypothesis, that TBV can be reliably estimated by CrV-measurement, data from routine MRI and 3D-laser-scanner measurements were analyzed in infants if no major structural brain anomaly was found in MR-imaging. To test whether CrV can be predicted by HC-measurements during infancy, data from routine follow-up visits were used from preterms born in a two year period. Preterms are invited for a routine follow-up visit (which includes laser scanning of the head) at an age of 3 months and, for further follow-ups at 6, 9 or 12 months. To compare accuracy of CrV measurement by other techniques, a puppet head was measured, using different 3D-measurement principles: (i) Structured light projection system, (ii) The non-invasive laser-shape-digitizer, and (iii) Structure-from-motion (SFM) technique.

OUTCOME MEASURES

TBV was compared with CrV using a Passing-Bablok-Regression. To determine how well HC predicts CrV, the coefficient of determinant (R²) was calculated for each age group.

RESULTS

CrV and TBV of 25 infants (median age 19 month, body weight of 11 kg) showed a median bias of -86.7 mm³ with a slightly smaller TBV (median of 1034.1 mm³, IQR 875.9 … 1179.8 mm³) than CrV (median 1092.2, IQR 950.5 … 1258.4 mm³). CrV was poorly estimated by HC, with R² between 0.79 and 0.87 at 3 and 9 month of age respectively. For the non-invasive laser-shape-digitizer and the SFM-technique the accuracy was good (radial coordinate differences ±0.3 vs. ±0.5 mm).

CONCLUSION

The present study provides convincing evidence that CrV can be used to estimate TBV in routine care, whereas HC is a poor predictor of individual CrV.

Emergent Prophylactic, Reparative and Restorative Brain Interventions for Infants Born Preterm With Cerebral Palsy

Worldwide, an estimated 15 million babies are born preterm (<37 weeks' gestation) every year. Despite significant improvements in survival rates, preterm infants often face a lifetime of neurodevelopmental disability including cognitive, behavioral, and motor impairments. Indeed, prematurity remains the largest risk factor for the development of cerebral palsy. The developing brain of the preterm infant is particularly fragile; preterm babies exhibit varying severities of cerebral palsy arising from reductions in both cerebral white and gray matter volumes, as well as altered brain microstructure and connectivity. Current intensive care therapies aim to optimize cardiovascular and respiratory function to protect the brain from injury by preserving oxygenation and blood flow. If a brain injury does occur, definitive diagnosis of cerebral palsy in the first few hours and weeks of life is difficult, especially when the lesions are subtle and not apparent on cranial ultrasound. However, early diagnosis of mildly affected infants is critical, because these are the patients most likely to respond to emergent treatments inducing neuroplasticity via high-intensity motor training programs and regenerative therapies involving stem cells. A current controversy is whether to test universal treatment in all infants at risk of brain injury, accepting that some patients never required treatment, because the perceived potential benefits outweigh the risk of harm. Versus, waiting for a diagnosis before commencing targeted treatment for infants with a brain injury, and potentially missing the therapeutic window. In this review, we discuss the emerging prophylactic, reparative, and restorative brain interventions for infants born preterm, who are at high risk of developing cerebral palsy. We examine the current evidence, considering the timing of the intervention with relation to the proposed mechanism/s of action. Finally, we consider the development of novel markers of preterm brain injury, which will undoubtedly lead to improved diagnostic and prognostic capability, and more accurate instruments to assess the efficacy of emerging interventions for this most vulnerable group of infants.

Assessment of neonatal brain volume and growth at different postmenstrual ages by conventional MRI

Data regarding neonatal brain volumes represent a basis for monitoring early brain development, and large sample of neonatal brain volume data has not been well described. This study was focused on neonatal brain volumes at different postmenstrual ages (PMA) and postnatal age (PNA).A cohort of 415 neonates with PMA 30 to 43 weeks were recruited for the determination of brain volumes. Intracranial cavity (ICC), total brain tissue (TBT), and cerebrospinal fluid (CSF) were evaluated on the basis of T1-weighted sagittal plane magnetic resonance images. Brain magnetic resonance imaging was assessed using maturation scoring system and multiple linear regression analysis was conducted to forecast the effect factors of brain volumes.TBT volume reached a peak growth at 39 to 40 weeks, ICC volume presented peak growth later at around 43 to 44 weeks, and CSF had a cliff fallen at 37 to 38 weeks PMA at scan. The maturation score increased along with PMA, and the TBT and CSF volumes were significantly different between higher and lower gestational age (GA) groups. The ICC and TBT volumes in higher GA group were larger than lower GA group. Most infants in higher GA group had higher TMS than those in lower GA group. Gender, PMA, PNA, and birth weight were predictors of TBT and ICC volumes.Our results showed that premature volumes of ICC and TBT enlarged with the increasing PMA, while volumes of CSF decreased at 37 weeks. Premature earlier to leave the uterus can lead to brain mature retard although they had the same GA compared with those later birth neonates.

Academic performance of children born preterm: a meta-analysis and meta-regression

BACKGROUND

Advances in neonatal healthcare have resulted in decreased mortality after preterm birth but have not led to parallel decreases in morbidity. Academic performance provides insight in the outcomes and specific difficulties and needs of preterm children.

OBJECTIVE

To study academic performance in preterm children born in the antenatal steroids and surfactant era and possible moderating effects of perinatal and demographic factors.

DESIGN

PubMed, Web of Science and PsycINFO were searched for peer-reviewed articles. Cohort studies with a full-term control group reporting standardised academic performance scores of preterm children (<37 weeks of gestation) at age 5 years or older and born in the antenatal steroids and surfactant era were included. Academic test scores and special educational needs of preterm and full-term children were analysed using random effects meta-analysis. Random effects meta-regressions were performed to explore the predictive role of perinatal and demographic factors for between-study variance in effect sizes.

RESULTS

The 17 eligible studies included 2390 preterm children and 1549 controls. Preterm children scored 0.71 SD below full-term peers on arithmetic (p<0.001), 0.44 and 0.52 SD lower on reading and spelling (p<0.001) and were 2.85 times more likely to receive special educational assistance (95% CI 2.12 to 3.84, p<0.001). Bronchopulmonarydysplasia explained 44% of the variance in academic performance (p=0.006).

CONCLUSION

Preterm children born in the antenatal steroids and surfactant era show considerable academic difficulties. Preterm children with bronchopulmonarydysplasia are at particular risk for poor academic outcome.

Cognitive outcomes in children and adolescents born very preterm: a meta-analysis

AIM

To estimate the association between very preterm birth (<32wks' gestation) and intelligence, executive functioning, and processing speed throughout childhood and adolescence, and to examine the effects of gestational age, birthweight, and age at assessment.

METHOD

Studies were included if children were born at earlier than 32 weeks' gestation, aged 4 to 17 years, had an age-matched term control group, and if the studies used standardized measures, were published in an English-language peer-reviewed journal, and placed no restrictions on participants based on task performance.

RESULTS

We evaluated 6163 children born very preterm and 5471 term-born controls from 60 studies. Children born very preterm scored 0.82 SDs (95% confidence interval [CI] 0.74-0.90; p<0.001) lower on intelligence tests, 0.51 SDs (95% CI 0.44-0.58; p<0.001) lower on measures of executive functioning, and 0.49 SDs (95% CI 0.39-0.60; p<0.001) lower on measures of processing speed than term-born controls. Gestational age and birthweight were associated with study effect size in intelligence and executive functioning of younger children only. Age at assessment was not associated with study effect size.

INTERPRETATION

Children born very preterm have medium to large deficits in these cognitive domains.

WHAT THIS PAPER ADDS

This meta-analysis is centred on very preterm birth and three cognitive domains. The three critical cognitive domains are intelligence, executive functioning, and processing speed.

Extremely preterm children exhibit increased interhemispheric connectivity for language: findings from fMRI-constrained MEG analysis

Children born extremely preterm are at significant risk for cognitive impairment, including language deficits. The relationship between preterm birth and neurological changes that underlie cognitive deficits is poorly understood. We use a stories-listening task in fMRI and MEG to characterize language network representation and connectivity in children born extremely preterm (n = 15, <28 weeks gestation, ages 4-6 years), and in a group of typically developing control participants (n = 15, term birth, 4-6 years). Participants completed a brief neuropsychological assessment. Conventional fMRI analyses revealed no significant differences in language network representation across groups (p > .05, corrected). The whole-group fMRI activation map was parcellated to define the language network as a set of discrete nodes, and the timecourse of neuronal activity at each position was estimated using linearly constrained minimum variance beamformer in MEG. Virtual timecourses were subjected to connectivity and network-based analyses. We observed significantly increased beta-band functional connectivity in extremely preterm compared to controls (p < .05). Specifically, we observed an increase in connectivity between left and right perisylvian cortex. Subsequent effective connectivity analyses revealed that hyperconnectivity in preterms was due to significantly increased information flux originating from the right hemisphere (p < 0.05). The total strength and density of the language network were not related to language or nonverbal performance, suggesting that the observed hyperconnectivity is a "pure" effect of prematurity. Although our extremely preterm children exhibited typical language network architecture, we observed significantly altered network dynamics, indicating reliance on an alternative neural strategy for the language task.

Hand Preference and Cognitive, Motor, and Behavioral Functioning in 10-Year-Old Extremely Preterm Children

The association of hand preference (left, mixed, and right) with cognitive, academic, motor, and behavioral function was evaluated in 864 extremely preterm children at 10 years of age. Left-handed and right-handed children performed similarly but mixed-handed children had greater odds of functional deficits across domains than right-handed children.

Antenatal and Neonatal Antecedents of Executive Dysfunctions in Extremely Preterm Children

To find out why children born extremely preterm are at heightened risk of executive dysfunctions, the authors assessed 716 children who were 10 years old born extremely preterm whose IQ was ≥ 70. A working memory dysfunction (n = 169), an inhibition dysfunction (n = 360), a switching dysfunction (355), and all 3 (executive dysfunction; n = 107) were defined on the basis of Z-scores ≤ -1 on the Differential Ability Scales-II Working Memory composite, and/or on the NEPSY-II Inhibition-Inhibition and Inhibition-Switching subtests. All risk profiles include an indicator of socioeconomic disadvantage. The risk profile of each of the 3 individual dysfunctions includes an indicator of the newborn's immaturity, and the risk profiles of the inhibition dysfunction and switching dysfunction also include an indicator of inflammation. Only the switching dysfunction was associated with fetal growth restriction. The risk factors for executive dysfunction can be subsumed under the 4 themes of socioeconomic disadvantage, immaturity/vulnerability, inflammation, and fetal growth restriction.

Association between cognition and the retinal microvasculature in 11-year old children born preterm or at term

BACKGROUND

Retinal microvessels can be visualized non-invasively and mirror the status of the cerebral microvasculature.

AIMS

To investigate whether in young children born prematurely or at term cognitive performance is related to retinal microvascular traits.

STUDY DESIGN, SUBJECTS

In 93 prematurely born infants (birth weight < 1000 g) and 87 controls born at term, we measured head circumference (HC) and determined intelligence quotient (IQ) by combining matrix reasoning and spatial span (Wechsler Non-Verbal test, Dutch version) and post-processed retinal photographs using Singapore I Vessel Assessment software (version 3.6).

OUTCOME MEASURES, RESULTS

Compared with controls, cases had smaller HC (51.7 vs 53.4 cm; p < 0.001), lower IQ (93.9 vs 109.2; p < 0.001), smaller retinal arteriolar (CRAE; 162.7 vs 174.0 μm; p < 0.001) and venular (CRVE; 234.9 vs 242.8 μm; p = 0.003) diameters and CRAE/CRVE ratio (0.69 vs 0.72; p = 0.001). A 1-SD decrease in CRAE was associated with smaller HC (-0.53 cm; p < 0.001) and lower total IQ (-3.74; p < 0.001), matrix reasoning (-1.77; p = 0.004) and spatial span (-2.03; p = 0.002). These associations persisted after adjustment for sex and age and risk factors for cognitive impairment, including blood pressure, body mass index and parental educational attainment.

CONCLUSIONS

HC, total IQ, matrix reasoning and spatial span decrease with smaller retinal arteriolar diameter. Our findings suggest that maldevelopment of the cerebral microcirculation, as mirrored by the retinal microvasculature, has lasting effects on the growth of the brain and cognitive performance of prematurely born children.

A gradient relationship between low birth weight and IQ: A meta-analysis

Multiple studies have reported that individuals with low birth weights (LBW, <2500 g) have a lower intelligence quotient (IQ) than those with normal birth weights (NBW, ≥2500 g). Based on 57 eligible individual studies including 12,137 participants, we performed a meta-analysis to estimate the association between low birth weight and individuals' IQ scores (IQs). The pooled weight mean difference (WMD) in IQs between NBW and LBW individuals was 10 (95% CI 9.26-11.68). The WMD was stable regardless of age. No publication bias was detected. The mean IQs of the extremely low birth weight (ELBW, <1000 g), very low birth weight (VLBW, 1000-1499 g), moderately low birth weight (MLBW, 1500-2499 g) and NBW individuals were 91, 94, 99 and 104, respectively. Additionally, the WMD in IQs with NBW were 14, 10 and 7 for ELBW, VLBW, and MLBW individuals, respectively. Two studies permitted estimates of the influence of social determinants of health to the discrepancy in IQs, which was 13%. Since IQ is inherited and influenced by environmental factors, parental IQs and other factors contribute to residual confounding of the results. As the conclusion was based on population studies, it may not be applicable to a single individual.

Associations of Newborn Brain Magnetic Resonance Imaging with Long-Term Neurodevelopmental Impairments in Very Preterm Children

OBJECTIVE

To determine the relationship between brain abnormalities on newborn magnetic resonance imaging (MRI) and neurodevelopmental impairment at 7 years of age in very preterm children.

STUDY DESIGN

A total of 223 very preterm infants (<30 weeks of gestation or <1250 g) born at Melbourne's Royal Women's Hospital had a brain MRI scan at term equivalent age. Scans were scored using a standardized system that assessed structural abnormality of cerebral white matter, cortical gray matter, deep gray matter, and cerebellum. Children were assessed at 7 years on measures of general intelligence, motor functioning, academic achievement, and behavior.

RESULTS

One hundred eighty-six very preterm children (83%) had both an MRI at term equivalent age and a 7-year follow-up assessment. Higher global brain, cerebral white matter, and deep gray matter abnormality scores were related to poorer intelligence quotient (IQ) (Ps < .01), spelling (Ps < .05), math computation (Ps < .01), and motor function (Ps < .001). Higher cerebellum abnormality scores were related to poorer IQ (P = .001), math computation (P = .018), and motor outcomes (P = .001). Perinatal, neonatal, and social confounders had little effect on the relationships between the MRI abnormality scores and outcomes. Moderate-severe global abnormality on newborn MRI was associated with a reduction in IQ (-6.9 points), math computation (-7.1 points), and motor (-1.9 points) scores independent of the other potential confounders.

CONCLUSIONS

Structured evaluation of brain MRI at term equivalent is predictive of outcome at 7 years of age, independent of clinical and social factors.

Prediction of cognitive and motor outcome of preterm infants based on automatic quantitative descriptors from neonatal MR brain images

This study investigates the predictive ability of automatic quantitative brain MRI descriptors for the identification of infants with low cognitive and/or motor outcome at 2-3 years chronological age. MR brain images of 173 patients were acquired at 30 weeks postmenstrual age (PMA) (n = 86) and 40 weeks PMA (n = 153) between 2008 and 2013. Eight tissue volumes and measures of cortical morphology were automatically computed. A support vector machine classifier was employed to identify infants who exhibit low cognitive and/or motor outcome (<85) at 2-3 years chronological age as assessed by the Bayley scales. Based on the images acquired at 30 weeks PMA, the automatic identification resulted in an area under the receiver operation characteristic curve (AUC) of 0.78 for low cognitive outcome, and an AUC of 0.80 for low motor outcome. Identification based on the change of the descriptors between 30 and 40 weeks PMA (n = 66) resulted in an AUC of 0.80 for low cognitive outcome and an AUC of 0.85 for low motor outcome. This study provides evidence of the feasibility of identification of preterm infants at risk of cognitive and motor impairments based on descriptors automatically computed from images acquired at 30 and 40 weeks PMA.

Real-Life Impact of Executive Function Impairments in Adults Who Were Born Very Preterm

OBJECTIVES

Children and adolescents who were born very preterm (≤32 weeks' gestation) are vulnerable to experiencing cognitive problems, including in executive function. However, it remains to be established whether cognitive deficits are evident in adulthood and whether these exert a significant effect on an individual's real-lifeachievement.

METHODS

Using a cross-sectional design, we tested a range of neurocognitive abilities, with a focus on executive function, in a sample of 122 very preterm individuals and 89 term-born controls born between 1979 and 1984. Associations between executive function and a range of achievement measures, indicative of a successful transition to adulthood, were examined.

RESULTS

Very preterm adults performed worse compared to controls on measures of intellectual ability and executive function with moderate to large effect sizes. They also demonstrated significantly lower achievement levels in terms of years spent in education, employment status, and on a measure of functioning in work and social domains. Results of regression analysis indicated a stronger positive association between executive function and real-life achievement in the very preterm group compared to controls.

CONCLUSIONS

Very preterm born adults demonstrate executive function impairments compared to full-term controls, and these are associated with lower achievement in several real-life domains. (JINS, 2017, 23, 381-389).

Prognostic neurodevelopmental testing of preterm infants: do we need to change the paradigm?

Longitudinal follow-up with assessment of developmental status at about 2 years of age is routine for high-risk newborns. The results of these assessments can be used for many purposes, including helping physicians, parents, and teachers plan educational or developmental interventions. These assessments also provide outcome measures for clinical research studies. Outcome results may also serve as a source of information for clinicians when counseling parents regarding provision of care for extreme preterm infants. Consideration should be given to use of different outcome metrics based on the purpose for testing. Categorization of composite cognitive, motor and neurosensory findings to define levels of impairment should be limited to research. Planning for individual interventions is better guided by descriptive findings. Current tools for assessing neurodevelopmental status at 2 years of age have important limitations. First, outcomes at early ages do not always predict function later in life. They are, at best, an estimate of longer-term outcomes, with important individual variation. For infants without severe neurologic injury, postnatal environmental factors play a predominant role in determining long-term cognitive and academic outcomes. Further investigations should assess quality of life and other considerations that are important for parents when making decisions about neonatal intensive care unit care for their infant.

A longitudinal study of associations between psychiatric symptoms and disorders and cerebral gray matter volumes in adolescents born very preterm

Background

Being born preterm with very low birthweight (VLBW ≤ 1500 g) poses a risk for cortical and subcortical gray matter (GM) abnormalities, as well as for having more psychiatric problems during childhood and adolescence than term-born individuals. The aim of this study was to investigate the relationship between cortical and subcortical GM volumes and the course of psychiatric disorders during adolescence in VLBW individuals.

Methods

We followed VLBW individuals and term-born controls (birth weight ≥10th percentile) from 15 (VLBW;controls n = 40;56) to 19 (n = 44;60) years of age. Of these, 30;37 individuals were examined longitudinally. Cortical and subcortical GM volumes were extracted from MRPRAGE images obtained with the same 1.5 T MRI scanner at both time points and analyzed at each time point with the longitudinal stream of the FreeSurfer software package 5.3.0. All participants underwent clinical interviews and were assessed for psychiatric symptoms and diagnosis (Schedule for Affective Disorders and Schizophrenia for School-age Children, Children’s Global Assessment Scale, Attention-Deficit/Hyperactivity Disorder Rating Scale-IV). VLBW adolescents were divided into two groups according to diagnostic status from 15 to 19 years of age: persisting/developing psychiatric diagnosis or healthy/becoming healthy.

Results

Reduction in subcortical GM volume at 15 and 19 years, not including the thalamus, was limited to VLBW adolescents with persisting/developing diagnosis during adolescence, whereas VLBW adolescents in the healthy/becoming healthy group had similar subcortical GM volumes to controls. Moreover, across the entire VLBW group, poorer psychosocial functioning was predicted by smaller subcortical GM volumes at both time points and with reduced GM volume in the thalamus and the parietal and occipital cortex at 15 years. Inattention problems were predicted by smaller GM volumes in the parietal and occipital cortex.

Conclusions

GM volume reductions in the parietal and occipital cortex as well as smaller thalamic and subcortical GM volumes were associated with the higher rates of psychiatric symptoms found across the entire VLBW group. Significantly smaller subcortical GM volumes in VLBW individuals compared with term-born peers might pose a risk for developing and maintaining psychiatric diagnoses during adolescence. Future research should explore the possible role of reduced cortical and subcortical GM volumes in the pathogenesis of psychiatric illness in VLBW adolescents.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0793-0) contains supplementary material, which is available to authorized users.

Gestational Age and Kindergarten School Readiness in a National Sample of Preterm Infants

OBJECTIVE

To examine the association of gestational age with school readiness in kindergarten reading and math skills. We hypothesized that compared with infants born at 39-41 weeks, infants born at lower gestational ages would have poorer school readiness.

STUDY DESIGN

The study sample comprised 5250 children from the Early Childhood Longitudinal Study, Birth Cohort, assessed with specialized reading and math assessments at kindergarten. Poor school readiness was characterized by reading and math theta scores ≥1.5 SD below the sample mean. The aOR and 95% CI of poor school readiness were estimated using multivariate logistic regression, examining gestational age continuously and categorically (very preterm [VPT], moderate/late preterm [M/LPT], early term [ET], and term). Pairwise comparisons were performed to test for differences by gestational age category.

RESULTS

There was an association between gestational age and poor school readiness for reading and math, with the suggestion of a threshold effect in children born at ≥32 weeks gestation. In adjusted models, in VPT infants, the aORs of poor school readiness in reading and math were 2.58 (95% CI, 1.29-5.15) and 3.38 (95% CI, 1.66-6.91), respectively. For infants born M/LPT and ET, the odds of poor school readiness in reading did not differ from those of children born full-term, however.

CONCLUSIONS

Compared with term infants, the highest odds of poor school readiness in reading and math were seen in VPT infants, with lower odds of poor school readiness in children born at ≥32 weeks gestation. Ongoing developmental surveillance before kindergarten is indicated for VPT infants.