Developmental correlates of head circumference at birth and two years in a cohort of extremely low gestational age newborns

Association of Growth During Infancy with Neurodevelopment and Obesity in Children Born Very Preterm: The Environmental Influences on Child Health Outcomes Cohort

OBJECTIVE

To evaluate associations between change in weight z score after neonatal intensive care unit (NICU) discharge and neurodevelopmental outcomes and obesity at 12-48 months of age among individuals born very preterm.

STUDY DESIGN

This secondary analysis used data from infants born very preterm participating in the Environmental influences on Child Health Outcomes cohort (n = 1400). Growth during infancy was calculated as change in weight z score between NICU discharge and follow-up at a mean of 27 months of age. Very low weight gain was defined as a change in weight z score <-1.67; very high weight gain was a change in weight z score >1.67. Neurodevelopmental outcomes included the Bayley Scales of Infant and Toddler Development, Child Behavior Checklist 1.5-5 years, and Modified Checklist for Autism in Toddlers. Multivariable linear regression was used to estimate associations between increase in weight z score and neurodevelopmental outcomes.

RESULTS

Very low weight gain between NICU discharge and follow-up (experienced by 6.4% of participants) was associated with lower scores on cognitive (adjusted mean difference: -4.26; 95% CI: -8.55, -0.04) and language (adjusted mean difference: -4.80; 95% CI: -9.70, -0.11) assessments. Very high weight gain (experienced by 13.6% of participants) was associated with an increased obesity risk (adjusted relative risk: 6.20; 95% CI: 3.99, 9.66) but not with neurodevelopmental outcomes.

CONCLUSIONS

Very high weight gain in the first 12-48 months after NICU discharge was associated with a higher risk of obesity at follow-up; very low weight gain was associated with lower scores on cognitive and language assessments.

Longitudinal relations of prematurity and fetal growth restrictions with hyperactivity/inattention and aggression/delinquency

BACKGROUND

It is the aim of this study to analyze the longitudinal relationship between premature birth and low birth weight and the reciprocal influence between hyperactive/inattentive behavior and aggressive/delinquent behavior problems in children from early to late childhood.

METHODS

This study contains data from the German Erlangen-Nuremberg Development and Prevention Study. It applies prospective longitudinal path analyses on data obtained from postnatal pediatric assessments as well as later psychosocial behavior assessments by teachers and parents on N = 667 children, out of which n = 83 children (12.44%) were born preterm/small for gestational age.

RESULTS

The results show direct effects of birth complications at the beginning of preschool on hyperactivity/inattentiveness (teacher rating: ß = 0.28; p = 0.017; parent rating: ß = 0.32; p = 0.005), but not on aggression/delinquency (teacher rating: ß = 0.002; p = 0.427; parent rating: ß = 0.12; p = 0.324). Reciprocal effects between aggression/delinquency and hyperactivity/inattentiveness were stable at the end of elementary school, but not at the end of preschool across informants.

CONCLUSION

Our results support a differentiated view on the potential development of behavior problems after birth complications and the demand for early prevention measures.

IMPACT STATEMENT

Our results extend to the existing body of research by providing insight into the longitudinal effects of prematurity and fetal growth restrictions on hyperactive and aggressive/delinquent behavioral problems throughout a rather long period of development in childhood. The results show direct effects of birth complications on the development of hyperactivity for boys, but not for girls across informants. No direct effects of birth complications on aggression/delinquency are found. Our findings speak against too simple views on behavioral consequences of birth complications and thus can relieve too anxious parents, however close monitoring of the behavioral development of respective children is indicated.

A digital twin of the infant microbiome to predict neurodevelopmental deficits

Despite the recognized gut-brain axis link, natural variations in microbial profiles between patients hinder definition of normal abundance ranges, confounding the impact of dysbiosis on infant neurodevelopment. We infer a digital twin of the infant microbiome, forecasting ecosystem trajectories from a few initial observations. Using 16S ribosomal RNA profiles from 88 preterm infants (398 fecal samples and 32,942 abundance estimates for 91 microbial classes), the model (Q-net) predicts abundance dynamics with R2 = 0.69. Contrasting the fit to Q-nets of typical versus suboptimal development, we can reliably estimate individual deficit risk (Mδ) and identify infants achieving poor future head circumference growth with ≈76% area under the receiver operator characteristic curve, 95% ± 1.8% positive predictive value at 98% specificity at 30 weeks postmenstrual age. We find that early transplantation might mitigate risk for ≈45.2% of the cohort, with potentially negative effects from incorrect supplementation. Q-nets are generative artificial intelligence models for ecosystem dynamics, with broad potential applications.

Impact of increased paternal age on neonatal outcomes in very-low-birth-weight infants

OBJECTIVE

Despite the trend of increasing paternal age, its impact on neonatal outcomes, particularly in preterm infants, has not been thoroughly investigated. We aimed to evaluate the perinatal characteristics and neonatal outcomes associated with paternal age.

METHODS

Electronic medical records of very low-birthweight infants admitted to our unit from July 2013 to March 2022 were reviewed. Infants grouped according to paternal age (<35 years, 35-39 years, and ≥40 years) were analyzed for differences in perinatal findings and neonatal outcomes.

RESULTS

A total of 637 infants were included (194, 294, and 149 in the <35, 35-39, and ≥40 years groups, respectively). The increase in paternal age paralleled the increase in maternal age. The Z-score of head circumference at birth was significantly different between the groups, showing the lowest median value in the ≥40 years group. Small-for-gestational age (Odds ratio 71.074, p < .001, 95% confidence interval 19.337 - 261.236) and male sex (Odds ratio 3.309, p < .034, 95% confidence interval 1.089 - 8.425), but not paternal or maternal age groups were significant factors associated with head circumference Z-scores less than -2 standard deviation based on the multivariable logistic regression analysis. Infants affected by chromosomal or genetic anomaly were more frequently identified (3.4 vs 0.0 vs 0.5%) in the ≥40 years group than in the other two groups. When infants with anomalies or critical illnesses were excluded, overall neonatal outcomes did not statistically differ according to paternal age.

CONCLUSION

Although increased paternal age ≥40 years may be associated with relatively smaller head circumferences, the impact on fetal head growth does not imply a definite risk for microcephaly. Nonetheless, based on the possible negative impact on chromosomal/genetic anomaly, increased paternal age warrants attention, even though neonatal outcomes concerning prematurity were not significantly affected. A large-scale longitudinal study is needed to further elucidate the impact of advanced paternal age in preterm infants and provide guidelines for appropriate antenatal counseling and surveillance.

Stereophotogrammetry can feasibly assess 'physiological' longitudinal three-dimensional head development of very preterm infants from birth to term

Head development is a surrogate for brain development in infants and is related to neurocognitive outcome. There is only limited knowledge on early extra-uterine head shape and size assessment in very preterm infants. Here, 26 very preterm infants with a mean gestational age of 29.1 ± 2.2 weeks and a mean birth weight of 1273.8 ± 427.7 g underwent serial stereophotogrammetric 3D head imaging in weekly intervals from birth to term-equivalent age. The main outcome was the longitudinal assessment of the 'physiological' preterm head development with cephalometric size (head circumference, cranial volume) and shape parameters (cranial index, cranial vault asymmetry index) according to chronological and postmenstrual age (PMA). Potential clinical risk factors for the development of an abnormal low cranial index (dolichocephaly) were analysed. In serial measurements of 26 infants, the estimated head volume (95% confidence interval) increased from 244 (226-263) cm3 at 28 weeks PMA to 705 (688-721) cm3 at 40 weeks PMA. Moderate or severe dolichocephaly occurred in 21/26 infants (80.8%). Cranial index decreased over time (72.4%; 70.7-74 95% confidence interval). Brachycephaly and plagiocephaly were uncommon. No risk factors for severe dolichocephaly were identified. Our study shows that early detection of head shape and size anomalies utilizing 3D stereophotogrammetry is feasible and safe even in very preterm infants < 1500 g and/or < 32 weeks. 3D stereophotogrammetry could be used for timely identification of infants at risk for head shape anomalies. No specific risk factors for head shape anomalies were identified, especially not mode and duration of respiratory support.

Extreme prematurity: Risk and resiliency

Individuals born extremely preterm (before 28 weeks of gestation) comprise only about 0.7% of births in the United States and an even lower proportion in other high resource countries. However, these individuals account for a disproportionate number of children with cerebral palsy, intellectual deficit, autism spectrum disorder, attention deficit hyperactivity disorder, and epilepsy. This review describes two large multiple center cohorts comprised of individuals born extremely preterm: the EPICURE cohort, recruited 1995 in the United Kingdom and the Republic of Ireland, and the Extremely Low Gestational Age Newborn (ELGAN), recruited 2002-2004 in five states in the United States. The primary focus of these studies has been neurodevelopmental disorders, but also of interest are growth, respiratory illness, and parent- and self-reported global health and well-being. Both of these studies indicate that among individuals born extremely preterm the risks of most neurodevelopmental disorders are increased. Early life factors that contribute to this risk include perinatal brain damage, some of which can be identified using neonatal head ultrasound, bronchopulmonary dysplasia, and neonatal systemic inflammation. Prenatal factors, particularly the family's socioeconomic position, also appear to contribute to risk. For most adverse outcomes, the risk is higher in males. Young adults born extremely preterm who have neurodevelopmental impairment, as compared to those without such impairment, rate their quality of life lower. However, young adults born extremely preterm who do not have neurodevelopmental impairments rate their quality of life as being similar to that of young adults born at term. Finally, we summarize the current state of interventions designed to improve the life course of extremely premature infants, with particular focus on efforts to prevent premature birth and on postnatal efforts to prevent adverse neurodevelopmental outcomes.

Head Circumference within the Normal Range and Neurodevelopmental Outcomes in Preterm Infants

OBJECTIVE

We sought to determine if variation in head circumference (HC) within the range of normal (5th-10th and 90th-95th percentile) is associated with poor neurodevelopmental outcomes (NDO), which defined as mild or moderate delay by Bayley II psychometrics (BSID-II).

STUDY DESIGN

This is a secondary analysis of a randomized controlled trial assessing the benefits of magnesium for the prevention of cerebral palsy. Fetuses with a normal HC at birth defined as within 5th to 95th percentile were included. NDO were assessed at age 2 with BSID-II. Moderate delay was defined as a score <70 and mild delay as <85. HC was classified as small normal (5th-10th percentile), normal (10th-90th percentile), and large normal (90th-95th percentile). Logistic regression models adjusted for confounding. Linear regression models estimated the impact for every 1 cm of change in HC.

RESULTS

Of 1,236 included infants, 111 (8%) had small normal HC; 1,058 (85%) had normal HC; and 67 (5%) had large normal HC. Baseline characteristics were similar between groups. There was no association with changes in HC within the range of normal and developmental indices. When considered as a continuous variable, every 1 cm increase in HC was also not associated with a significant change in developmental indices.

CONCLUSION

Within the normal range (5th-95th percentile), changes in HC did not correlate with changes in NDO at 2 years as measured by Bayley II scales.

KEY POINTS

· It is unknown if variations in normal HC are associated with poor neurodevelopmental outcomes.. · Alterations in HC within the range of normal (5th-95th percentile) are not associated with adverse NDO.. · When considered as a continuous variable, a 1 cm increase in HC is not associated with adverse NDO.. · Changes in HC within the range of normal do not appear to be a pathologic change altering NDO..

Stereophotogrammetric head shape assessment in neonates is feasible and can identify distinct differences between term-born and very preterm infants at term equivalent age

The development of head shape and volume may reflect neurodevelopmental outcome and therefore is of paramount importance in neonatal care. Here, we compare head morphology in 25 very preterm infants with a birth weight of below 1500 g and / or a gestational age (GA) before 32 completed weeks to 25 term infants with a GA of 37–42 weeks at term equivalent age (TEA) and identify possible risk factors for non-synostotic head shape deformities. For three-dimensional head assessments, a portable stereophotogrammetric device was used. The most common and distinct head shape deformity in preterm infants was dolichocephaly. Severity of dolichocephaly correlated with GA and body weight at TEA but not with other factors such as neonatal morbidity, sex or total duration of respiratory support. Head circumference (HC) and cranial volume (CV) were not significantly different between the preterm and term infant group. Digitally measured HC and the CV significantly correlated even in infants with head shape deformities. Our study shows that stereophotogrammetric head assessment is feasible in all preterm and term infants and provides valuable information on volumetry and comprehensive head shape characteristics. In a small sample of preterm infants, body weight at TEA was identified as a specific risk factor for the development of dolichocephaly.

Head circumference in infants undergoing Foker process for long-gap esophageal atresia repair: Call for attention

INTRODUCTION

We extended our pilot study in infants following long-gap esophageal atresia (LGEA) repair to report head circumference, an easily obtainable indirect measure of brain size. Data are presented in the context of previously reported body weight and T2-weighted MRI measures of intracranial and brain volumes.

METHODS

Clinical information and head circumference were obtained for term-born (n = 13) and premature (n = 13) infants following LGEA repair with Foker process, as well as healthy term-born controls (n = 20) <1-year corrected age who underwent non-sedated research MRI. General Linear Model univariate analysis with corrected age at scan as a covariate and Bonferroni adjusted p values assessed group differences.

RESULTS

We report no difference in head circumference between the three groups. Such findings paralleled trends in body weight and total intracranial volume but not in brain volume as previously reported for the same pilot cohort.

DISCUSSION

Results suggest uncompromised somatic and head growth after repair of LGEA. In contrast, a novel finding of discrepancy between head circumference (novel data) and brain size (previously published data) in the same cohort suggests that head circumference might not be the best indirect measure of brain size in selected group of patients.

Association between head circumference at two years and second and fifth year cognition

Background

Head circumference (HC) measurement is routinely not performed in early childhood and there is conflicting information about its utility in literature. The current study analyses the association between HC at two years of age and cognition at two and five years of age.

Methods

A community based birth-cohort recruited between 2010 and 2012 was followed up till five years of age in an urban slum in Vellore, India. Children were recruited at birth after informed parental consent by consecutive sampling using eligibility criteria of healthy new-born, singleton pregnancy and family’s availability in the study area during follow-up. HC measured at two years of age was used as the exposure variable to calculate association with cognition at both two and five years of age. Cognitive domain of Bayley scale of infant development was used at two years of age and Wechsler Preschool Primary Scales of Intelligence at five years.

Results

Of the 251 enrolled children, 138 (55%) were girls and 71 (30%) belonged to lower socioeconomic status. At 2 years, 8.81% of children had HC < − 3SD. Compared to children with HC z-scores ≥ − 2 SD, those with measurements < − 3 SD had a lower cognition scores by − 2.21 [95% CI: − 3.87 - -0.56] at 2 years. Also, children with HC < − 3 SD at two years scored significantly lower scores in cognitive domains of verbal, − 7.35 [95% CI: − 11.78 - -2.92] and performance, − 7.07 [95% CI: − 11.77 - -2.36] intelligence at five years.

Conclusions

This study showed that smaller HC at 2 years of age was negatively associated with cognition at both 2 and 5 years of age. Early childhood HC measurements can be utilised as a cheaper screening tool to identify children at risk in LMIC settings. Further studies can confirm these findings in diverse settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02543-0.

Bacteroidota and Lachnospiraceae integration into the gut microbiome at key time points in early life are linked to infant neurodevelopment

The early life microbiome plays critical roles in host development, shaping long-term outcomes including brain functioning. It is not known which initial infant colonizers elicit optimal neurodevelopment; thus, this study investigated the association between gut microbiome succession from the first week of life and head circumference growth (HCG), the earliest validated marker for neurodevelopment. Fecal samples were collected weekly from a preterm infant cohort during their neonatal intensive care unit stay and subjected to 16S rRNA gene sequencing for evaluating gut microbiome composition, in conjunction with clinical data and head circumference measurements. Preterm infants with suboptimal HCG trajectories had a depletion in the abundance/prevalence of Bacteroidota and Lachnospiraceae, independent of morbidity and caloric restriction. The severity of gut microbiome depletion matched the timing of significant HCG pattern separation between study groups at 30-week postmenstrual age demonstrating a potential mediating relationship resultant from clinical practices. Consideration of the clinical variables indicated that optimal infant microbiome succession is primarily driven by dispersal limitation (i.e., delivery mode) and secondarily by habitat filtering (i.e., antibiotics and enteral feeding). Bacteroidota and Lachnospiraceae are known core taxa of the adult microbiome, with roles in dietary glycan foraging, beneficial metabolite production and immunity, and our work provides evidence that their integration into the gut microbiome needs to occur early for optimal neurodevelopment.

Quantile contours and allometric modelling for risk classification of abnormal ratios with an application to asymmetric growth-restriction in preterm infants

We develop an approach to risk classification based on quantile contours and allometric modelling of multivariate anthropometric measurements. We propose the definition of allometric direction tangent to the directional quantile envelope, which divides ratios of measurements into half-spaces. This in turn provides an operational definition of directional quantile that can be used as cutoff for risk assessment. We show the application of the proposed approach using a large dataset from the Vermont Oxford Network containing observations of birthweight (BW) and head circumference (HC) for more than 150,000 preterm infants. Our analysis suggests that disproportionately growth-restricted infants with a larger HC-to-BW ratio are at increased mortality risk as compared to proportionately growth-restricted infants. The role of maternal hypertension is also investigated.

Neurodevelopment of children exposed intra-uterus by Zika virus: A case series

The main goal of this manuscript was to investigate the neurodevelopment of children exposed by Zika virus in the intrauterine period who are asymptomatic at birth. Newborns with documented Zika virus exposure during the intrauterine period who were asymptomatic at birth were followed in the first two years of life for neurodevelopment using Bayley III test. Children were classified as having normal or delayed neurodevelopment for age based on most recent Bayley III evaluation results. Eighty-four infants were included in the study. The first Bayley III evaluation was performed at a mean chronological age of 9.7±3.1 month; 13 children (15%) had a delay in one of the three domains, distributed as follow: 10 (12%) in the language domain and 3 (3.5%) in the motor domain. The most recent Bayley III evaluation was performed at a mean age 15.3±3.1 months; 42 children (50%) had a delay in one of the three domains: 4 (5%) in cognition, 31 (37%) in language, and 20 (24%) in motor performance. There were no statistical differences in Gender, Gestational Age, Birth Weight and Head Circurference at birth between children with normal and delayed neurodevelopment for age. A very high proportion of children exposed ZIKV during pregnancy who were asymptomatic at birth demonstrated a delay in neurodevelopment, mainly in the language domain, the first two years of life.

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.

Association of Circulating Proinflammatory and Anti-inflammatory Protein Biomarkers in Extremely Preterm Born Children with Subsequent Brain Magnetic Resonance Imaging Volumes and Cognitive Function at Age 10 Years

OBJECTIVES

To examine elevated neonatal inflammatory and neurotrophic proteins from children born extremely preterm in relation to later childhood brain Magnetic Resonance Imaging volumes and cognition.

STUDY DESIGN

We measured circulating inflammation-related proteins and neurotrophic proteins on postnatal days 1, 7, and 14 in 166 children at 10 years of age (73 males; 93 females). Top quartile levels on ≥2 days for ≥3 inflammation-related proteins and for ≥4 neurotrophic proteins defined exposure. We examined associations among protein levels, brain Magnetic Resonance Imaging volumes, and cognition with multiple linear and logistic regressions.

RESULTS

Analyses were adjusted for gestational age at birth and sex. Children with ≥3 elevated inflammation-related proteins had smaller grey matter, brain stem/cerebellar, and total brain volumes than those without elevated inflammation-related proteins, adjusted for neurotrophic proteins. When adjusted for inflammation-related proteins, children with ≥4 neurotrophic proteins, compared with children with no neurotrophic proteins, had larger grey matter and total brain volumes. Higher grey matter, white matter, and cerebellum and brainstem volumes were significantly correlated with higher IQ. Grey and white matter volumes were correlated with each other (r = -0.18; P = .021), and cerebellum and brainstem was highly correlated with grey matter (r = 0.55; P < .001) and white matter (r = 0.29; P < .001). Adjusting for other brain compartments, cerebellum and brainstem was associated with IQ (P = .016), but the association with white matter was marginally significant (P = .051). Grey matter was not associated with IQ. After adjusting for brain volumes, elevated inflammation-related proteins remained significantly associated with a lower IQ, and elevated neurotrophic proteins remained associated with a higher IQ.

CONCLUSIONS

Newborn inflammatory and neurotrophin protein levels are associated with later brain volumes and cognition, but their effects on cognition are not entirely explained by altered brain volumes.

Establishing a conceptual framework of the impact of placental malaria on infant neurodevelopment

A novel conceptual framework to describe the relationship between placental malaria and adverse infant neurodevelopmental outcomes is proposed. This conceptual framework includes three distinct stages: (1) maternal and environmental risk factors for the development of placental malaria; (2) placental pathology and inflammation associated with placental malaria infection; and (3) postnatal impacts of placental malaria. The direct, indirect, and bidirectional effects of these risk factors on infant neurodevelopment across the three stages were critically examined. These factors ultimately culminate in an infant phenotype that not only leads to adverse birth outcomes, but also to increased risks of neurological, cognitive, and behavioural deficits that may impact the quality of life in this high-risk population. Multiple risk factors were identified in this conceptual framework; nonetheless, based on current evidence, a key knowledge gap is the uncertainty regarding which are the most important and how exactly they interact.

Combined predictors of neurodevelopment in very low birth weight preterm infants

OBJECTIVE

To evaluate the combined prognostic value of neurological examination, head circumference and cranial ultrasound for neurodevelopmental delay (NDD) in very low birth weight (VLBW, <1500 g) preterm infants.

METHODS

Prospective follow-up study. Preterm infants with VLWB were assessed for NDD using the Mullen Scales of Early Learning test at 24 months of corrected age. Abnormal neurological examination (≥2 deviant items of Hammersmith neurological examination), microcephaly and major ultrasound abnormalities, each performed at term age, were evaluated as predictors of NDD in a multivariable Poisson model.

RESULTS

35/132 infants (26.5%) had NDD. In the multivariable analysis, microcephaly (RR, 3.2; 95% CI, 1.6-6.7) and major ultrasound abnormalities (RR, 2.7; 95% CI, 1.3-5.7) were associated to NDD. The combination of the two tests showed the highest positive predictive value (100%; 95% CI, 51%-100%), while the combination of normal neurological examination, no major US findings and normal head size at term showed the highest negative predictive value (89%; 95% CI, 78%-95%). The maximum under receiver operating characteristic curve area was for microcephaly or major ultrasound abnormalities (AUC 0.74 (0.65-0.83)).

CONCLUSION

The combination of head circumference, cranial ultrasound and neurological examination at term age is useful to predict NDD in VLBW preterm infants.

Anthropometric measures at birth and early childhood are associated with neurodevelopmental outcomes among Bangladeshi children aged 2-3years

Among a cohort of children located in rural areas of Bangladesh affected by high levels of exposure to environmental metals, we investigated the associations between anthropometric measures, growth trajectory, and neurodevelopment at age 20-40months. Our study population included mothers and their children who participated in a longitudinal birth cohort study that took in place in the Pabna and Sirajdikhan areas of Bangladesh. Anthropometric measures including weight, length, and head circumference were measured at birth, age 12months, and age 20-40months. Neurodevelopment was assessed using Bayley Scales of Infant and Toddler Development Third Edition (BSID-III) multi-scale at age 20-40months. A total of 777 mother-child pairs were included. Higher anthropometric measures at 20-40months were associated with higher cognitive, language, and motor scores on BSID-III. For example, a 1-kg increment in birthweight was associated with an increase of 2.11 for cognitive score (p<0.0001), 1.63 for language score (p=0.006), and 0.89 for motor scores (p=0.03). Greater positive changes in growth parameters, or growth trajectory, between birth and 20-40months were also associated with higher BSID-III scores. These associations remained significant after adjusting for potential confounders and prenatal exposure to environmental metals. These findings suggest that even when taking into account high environmental metal exposures, prenatal and early childhood growth have strong associations with neurodevelopmental test scores in early childhood.

Cumulative Incidence of Seizures and Epilepsy in Ten-Year-Old Children Born Before 28 Weeks' Gestation

OBJECTIVE

We evaluated the incidence of seizures and epilepsy in the first decade of life among children born extremely premature (less than 28 weeks' gestation).

METHOD

In a prospective, multicenter, observational study, 889 of 966 eligible children born in 2002 to 2004 were evaluated at two and ten years for neurological morbidity. Complementing questionnaire data to determine a history of seizures, all caregivers were interviewed retrospectively for postneonatal seizures using a validated seizure screen followed by a structured clinical interview by a pediatric epileptologist. A second pediatric epileptologist established an independent diagnosis based on recorded responses of the interview. A third epileptologist determined the final diagnosis when evaluators disagreed (3%). Life table survival methods were used to estimate seizure incidence through ten years.

RESULTS

By age ten years, 12.2% (95% confidence interval: 9.8, 14.5) of children had experienced one or more seizures, 7.6% (95% confidence interval: 5.7, 9.5) had epilepsy, 3.2% had seizure with fever, and 1.3% had a single, unprovoked seizure. The seizure incidence increased with decreasing gestational age. In more than 75% of children with seizures, onset was after one year of age. Seizure incidence was comparable in both sexes. Two-thirds of those with epilepsy had other neurological disorders. One third of children with epilepsy were not recorded on the medical history questionnaire.

SIGNIFICANCE

The incidence of epilepsy through age ten years among children born extremely premature is approximately 7- to 14-fold higher than the 0.5% to 1% lifetime incidence reported in the general pediatric population. Seizures in this population are under-recognized, and possibly underdiagnosed, by parents and providers.

Neurodevelopmental Outcomes in 22 Children With Microcephaly of Different Etiologies

We examined longitudinal neurodevelopmental outcomes in a series of infants with microcephaly. Retrospective review identified neonatal intensive care unit follow-up clinic patients with a diagnostic code of microcephaly, verified by head circumference less than the fifth precentile (WHO growth curves). Data were collected regarding clinical history and developmental assessments by Capute Scales and gross motor age equivalent. Developmental Quotient (DQ) was age adjusted up until 2 years for preterm infants. Twenty-two infants had microcephaly. At latest follow-up (3-66 months, mean 27.2), 73% had delay (DQ < 70) in ≥1 area of development: gross motor 65% (mean DQ 56.8), visual-motor 59% (mean DQ 62.7), and language 59% (mean DQ 65.9). In this sample, postnatal onset and diagnosis of epilepsy were associated with lower DQs. We conclude that infants with microcephaly are at significant risk for delay across all aspects of development and for long-term disability. Postnatal etiologies of microcephaly and infants with comorbid epilepsy had worse outcomes.

Head Growth Trajectory and Neurodevelopmental Outcomes in Preterm Neonates

OBJECTIVES

To evaluate the association between head growth (HG) during neonatal and postdischarge periods and neurodevelopmental outcomes of preterm neonates of <29 weeks gestational age.

METHODS

We conducted a retrospective cohort study of infants <29 weeks gestational
age admitted between 2009 and 2011 to participating Canadian Neonatal Network
units and followed by Canadian Neonatal Follow-Up Network clinics. Differences in head circumference (ΔHC) z score were calculated for 3 time periods, which include admission to discharge, discharge to follow-up at 16-36 months, and admission to follow-up. These were categorized in 1 reference group (ΔHC z score between -1 and +1) and 4 study groups (ΔHC z score of <-2, between -2 to -1, +1 to +2, and >+2). Neurodevelopmental outcomes were compared with the reference group.

RESULTS

1973 infants met the inclusion criteria. Poor HG occurred frequently during the NICU admission (ΔHC z score <-2 in 24% infants versus 2% infants post-discharge) with a period of "catch-up" growth postdischarge. Significant neurodevelopmental impairment was higher in infants with the poorest HG from admission to follow-up (adjusted odds ratio 2.18, 95% confidence interval 1.50-3.15), specifically cognitive and motor delays. Infants with poor initial HG and catch-up postdischarge have a lower adjusted odds ratio of significant neurodevelopmental impairment (0.35, 95% CI 0.16-0.74). Infants with poor HG received a longer duration of parenteral nutrition and mechanical ventilation and had poor weight gain.

CONCLUSIONS

Poor HG during the neonatal and postdischarge periods was associated with motor and cognitive delays at 16 to 36 months.

Association between neonatal morbidities and head growth from birth until discharge in very-low-birthweight infants born preterm: a population-based study

AIM

To evaluate the possible association between major neonatal morbidities and poor head growth from birth to discharge home in very-low-birthweight (VLBW) infants born preterm.

METHOD

Population-based observational study comprising 12 992 infants (6340 male, 6652 female) of 24 to 32 weeks' gestation, and birthweight ≤1500g. Severe head growth failure (HGF) was defined as a decrease in head circumference z-score >2 z-scores, and moderate HGF as a decrease of 1 to 2 z-scores. Multinomial logistic regression analysis was applied to determine morbidities associated with HGF.

RESULTS

Severe HGF occurred in 4.5% and moderate HGF in 20.9% of infants. Each unit increase in head circumference z-score at birth was associated with increased odds for severe and moderate HGF (odds ratios [OR] 5.29, 95% confidence intervals [CI] 4.67-6.00, and OR 2.38, 95% CI 2.23-2.54 respectively). Both severe and moderate HGF were associated with respiratory distress syndrome (OR 2.03, 95% CI 1.58-2.62, and OR 1.66, 95% CI 1.48-1.85 respectively); bronchopulmonary dysplasia (OR 3.38, 95% CI 2.33-4.91, and OR 1.87, 95% CI 1.52-2.30 respectively); necrotizing enterocolitis (OR 2.89, 95% CI 2.04-4.09, and OR 1.72, 95% CI 1.38-2.16 respectively), and sepsis (OR 2.06, 95% CI 1.69-2.50, and OR 1.38, 95% CI 1.24-1.53 respectively).

INTERPRETATION

Major neonatal morbidities were associated with HGF in VLBW infants born preterm. Identification of whether this is a direct effect of these morbidities or mediated through nutritional or growth factors may enable interventions to improve postnatal head growth of infants born preterm.

Outcomes of Extremely Preterm Infants Born to Insulin-Dependent Diabetic Mothers

BACKGROUND AND OBJECTIVE

Little is known about in-hospital morbidities and neurodevelopmental outcomes among extremely preterm infants born to women with insulin-dependent diabetes mellitus (IDDM). We examined risks of mortality, in-hospital morbidities, and neurodevelopmental outcomes at 18 to 22 months' corrected age between extremely preterm infants of women with insulin use before pregnancy (IBP), with insulin use started during pregnancy (IDP), and without IDDM.

METHODS

Infants 22 to 28 weeks' gestation born or cared for at a Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network center (2006-2011) were studied. Regression models compared the association between maternal IDDM and timing of insulin use and the outcomes of the 3 groups.

RESULTS

Of 10 781 infants, 536 (5%) were born to women with IDDM; 58% had IBP, and 36% had IDP. Infants of mothers with IBP had higher risks of necrotizing enterocolitis (adjusted relative risk [RR] = 1.55 [95% confidence interval (CI) 1.17-2.05]) and late-onset sepsis (adjusted RR = 1.26 [95% CI 1.07-1.48]) than infants of mothers without IDDM. There was some indication of higher in-hospital mortality risk among infants of mothers with IBP compared with those with IDP (adjusted RR = 1.33 [95% CI 1.00-1.79]). Among survivors evaluated at 18 to 22 months' corrected age, average head circumference z score was lower for infants of mothers with IBP compared with those without IDDM, but there were no differences in risk of neurodevelopmental impairment.

CONCLUSIONS

In this cohort of extremely preterm infants, infants of mothers with IBP had higher risks of necrotizing enterocolitis, sepsis, and small head circumference.

Poor postdischarge head growth is related to a 10% lower intelligence quotient in very preterm infants at the chronological age of five years

AIM

This study examined the relationship between head growth and cognitive outcome at the age of five years in preterm infants born at less than 32 weeks of gestation from 2003 to 2009, as previous research has mostly focused on outcomes in toddlers.

METHODS

The head circumference of 273 very preterm infants born in Tyrol, Austria, was measured at birth, discharge, the corrected ages of three, 12 and 24 months and the chronological age of five years. Suboptimal head size was defined as a head circumference of more than one standard deviation below the mean. Full-scale intelligence quotient (IQ) at five years was determined using Wechsler Preschool and Primary Scales of Intelligence, third edition.

RESULTS

Infants with a suboptimal head size at the age of three months had a significantly lower median IQ than those with a normal head size (90 [20-122] versus 98 [20-138], p = 0.001) and from three months onwards they were more likely to exhibit cognitive delay.

CONCLUSION

A suboptimal head size from the age of three months was consistently related to a 10% lower IQ, and this study adds further evidence that head growth failure, especially during the early postdischarge period, is related to impaired cognitive abilities.

Comparing growth charts demonstrated significant deviations between the interpretation of postnatal growth patterns in very preterm infants

AIM

This study compared postnatal growth patterns calculated using different reference data in a large cohort of very preterm infants.

METHODS

The weight, length and head circumference of 551 very preterm infants born in the Tyrol, Austria, between 2003 and 2011, were obtained at birth, discharge and the corrected ages of three, 12 and 24 months. Growth data are presented as Z-scores in relation to four reference populations: LMS growth by Pan et al., Fenton preterm growth charts, the Euro-Growth Study Group and the World Health Organization (WHO) Anthro programme.

RESULTS

We observed significant differences in mean weight Z-scores using the four reference populations, with the WHO data being the highest. The mean head circumference Z-scores also differed significantly at all time points. We observed a pronounced gap in the microcephaly rate, which was 10 times higher at the age of 24 months if the Pan data were used instead of the WHO data.

CONCLUSION

Our findings revealed significant deviations between the interpretation of postnatal growth depending on the reference data used, with the most striking differences seen in head circumference. The choice of reference data, and particularly the conclusions drawn from the data, must be interpreted with utmost care.

Weight Status in the First 2 Years of Life and Neurodevelopmental Impairment in Extremely Low Gestational Age Newborns

OBJECTIVE

To examine the extent to which weight gain and weight status in the first 2 years of life relate to the risk of neurodevelopmental impairment in extremely preterm infants.

STUDY DESIGN

In a cohort of 1070 infants born between 23 and 27 weeks' gestation, we examined weight gain from 7-28 days of life (in quartiles) and weight z-score at 12 and 24 months corrected age (in 4 categories: <-2; ≥-2, <-1; ≥1, <1; and ≥1) in relation to these adverse neurodevelopmental outcomes: Bayley-II mental development index <55, Bayley-II psychomotor development index <55, cerebral palsy, Gross Motor Function Classification System ≥1 (cannot walk without assistance), microcephaly. We adjusted for confounders in logistic regression, stratified by sex, and performed separate analyses including the entire sample, and excluding children unable to walk without assistance (motor impairment).

RESULTS

Weight gain in the lowest quartile from 7-28 days was not associated with higher risk of adverse outcomes. Children with a 12-month weight z-score <-2 were at increased risk for all adverse outcomes in girls, and for microcephaly and Gross Motor Function Classification System ≥1 in boys. However, excluding children with motor impairment attenuated all associations except that of weight z-score <-2 with microcephaly in girls. Similarly, most associations of low weight z-score at 24 months with adverse outcomes were attenuated with exclusion of children with motor impairment.

CONCLUSION

Excluding children who have gross motor impairment appears to eliminate the association of low weight status with neurodevelopmental impairments at 2 years in extremely preterm infants.

Growth and nutritional risk in children with developmental delay

INTRODUCTION

Nutritional risk impacts outcome in developmental delay. The main objectives were to identify the incidence and factors contributing to growth faltering.

METHODS

Clinical data review was completed for 500 patients with developmental delay accepted to an Early Intervention service. Data was collected using the standardised parent nutrition screening checklist prior to and at time of initial dietary assessment. Data was compared to nutritional assessment data, GOSH and FSAI dietary guidelines. Weight category was determined using RCPCH growth and BMI charts. Statistical analysis was conducted using Statistical Package for the Social Sciences version 20 (IBM Statistics 20.0).

RESULTS

Nutritional risk was identified in 48.6 %. Weight categories were growth faltering (13.5 %), underweight (7.7 %), overweight (8.4 %) and obesity (4.3 %) at initial assessment. Growth faltering was correlated with age <1 year (p = 0.000) and with gestational age (p = 0.017) with highest rates identified in those born 32-36 weeks (3.6 %). Weight category was associated with introduction of solids pre 17 weeks recommendation (10.1 %), ANOVA demonstrating significance (P = 0.013). There was poor parental recognition of nutritional risk in 22.7 % of those assessed. Nutritional difficulties were common: 4.2 % were enterally fed, 7.7 % were on prescribed nutritional supplements, 29.1 % (n = 121) had feeding difficulties and 13.9 % (n = 58) had behavioural feeding difficulties. Iron intake did not meet the recommended intake in 20.9 % (n = 87), calcium in 4.5 % (n = 19). The prevalence of constipation was 21.6, 11.8 % of whom required medical management.

CONCLUSIONS

Developmental delay predisposes to nutritional deficits which influence outcome. Screening, assessment and timely interventions are warranted to prevent poorer developmental outcomes.

Postnatal growth in preterm infants and later health outcomes: a systematic review

In preterm infants, poor postnatal growth is associated with adverse neurocognitive outcomes; conversely, rapid postnatal growth is supposedly harmful for future development of metabolic diseases.

CONCLUSION

In this systematic review, observational studies reported consistent positive associations between postnatal weight or head growth and neurocognitive outcomes; however, there was limited evidence from the few intervention studies. Evidence linking postnatal weight gain to later adiposity and other cardiovascular disease risk factors in preterm infants was also limited.

Clinical phenotype of the recurrent 1q21.1 copy-number variant

PURPOSE

To characterize the clinical phenotype of the recurrent copy-number variation (CNV) at 1q21.1, we assessed the psychiatric and medical phenotypes of 1q21.1 deletion and duplication carriers ascertained through clinical genetic testing and family member cascade testing, with particular emphasis on dimensional assessment across multiple functional domains.

METHODS

Nineteen individuals with 1q21.1 deletion, 19 individuals with the duplication, and 23 familial controls (noncarrier siblings and parents) spanning early childhood through adulthood were evaluated for psychiatric, neurologic, and other medical diagnoses, and their cognitive, adaptive, language, motor, and neurologic domains were also assessed. Twenty-eight individuals with 1q21.1 CNVs (15 deletion, 13 duplication) underwent structural magnetic resonance brain imaging.

RESULTS

Probands with 1q21.1 CNVs presented with a range of psychiatric, neurologic, and medical disorders. Deletion and duplication carriers shared several features, including borderline cognitive functioning, impaired fine and gross motor functioning, articulation abnormalities, and hypotonia. Increased frequency of Autism Spectrum Disorder (ASD) diagnosis, increased ASD symptom severity, and increased prevalence of macrocephaly were observed in the duplication relative to deletion carriers, whereas reciprocally increased prevalence of microcephaly was observed in the deletion carriers.

CONCLUSIONS

Individuals with 1q21.1 deletions or duplications exhibit consistent deficits on motor and cognitive functioning and abnormalities in head circumference.Genet Med 18 4, 341-349.

Prenatal head growth and child neuropsychological development at age 14 months

OBJECTIVE

We sought to assess the association between prenatal head growth and child neuropsychological development in the general population.

STUDY DESIGN

We evaluated 2104 children at the age of 14 months from a population-based birth cohort in Spain. Head circumference (HC) was measured by ultrasound examinations at weeks 12, 20, and 34 of gestation and by a nurse at birth. Head growth was assessed using conditional SD scores between weeks 12-20 and 20-34. Trained psychologists assessed neuropsychological functioning using the Bayley Scales of Infant Development. Head size measurements at birth were transformed into a 3-category variable: microcephalic (<10th percentile), normocephalic (≥10th and <90th percentile), and macrocephalic (≥90th percentile) based on the cohort distribution. P values<.05 were considered statistically significant.

RESULTS

No overall associations were observed between HC or head growth and mental and psychomotor scores. In particular, no associations were found between HC at birth and mental scores (coefficient, 0.04; 95% confidence interval, -0.02 to 0.09) and between interval head growth (20-34 weeks) and mental scores (0.31; 95% confidence interval, -0.36 to 0.99). Upon stratification by microcephalic, normocephalic, or macrocephalic head size, results were imprecise, although there were some significant associations in the microcephalic and macrocephalic groups. Adjustment by various child and maternal cofactors did not affect results. The minimum sample size required for present study was 883 patients (β=2, α=0.05, power=0.80).

CONCLUSION

Overall prenatal and perinatal HC was not associated with 14-month-old neuropsychological development. Findings suggest HC growth during uterine life among healthy infants may not be an important marker of early-life neurodevelopment but may be marginally useful with specific populations.

Physical growth in the neonatal intensive-care unit and neuropsychological performance at preschool age in very preterm-born singletons

We studied the associations between early postnatal growth gains and neuropsychological outcome in very preterm-born children. Specifically, we wished to establish whether relationships exist between gains in head circumference (relative to gains in body-weight or length), from birth to hospital discharge, and intellectual, language, or motor, performance at preschool age. We used data from 127 preschoolers, born <33 weeks, all graduates of the William Beaumont Hospital Neonatal Intensive-Care Unit (NICU) in Royal Oak, MI. Cognitive, motor, and language outcomes were evaluated using the Wechsler Preschool and Primary Scales of Intelligence-Revised, Peabody Developmental Scales - 2(nd) Edition, and the Preschool Language Scale - 3(rd) Edition, respectively. Differences between Z-scores at birth and hospital discharge, calculated for three anthropometric measures (head circumference, weight, length), were variables of interest in separate simultaneous multiple regression procedures. We statistically adjusted for sex, socioeconomic status, birth weight, length of hospitalization, perinatal complications, and intrauterine growth. Examination of the relationships between anthropometric indices and outcome measures revealed a significant association between NICU head growth and global intelligence, with the Z-difference score for head circumference accounting for a unique portion of the variance in global intelligence (ηp(2) =.04). Early postnatal head growth is significantly associated with neuropsychological outcome in very preterm-born preschoolers. To conclude, despite its relative brevity, NICU stay, often overlapping with the end of 2(nd) and with the 3(rd) trimester of pregnancy, appears to be a sensitive developmental period for brain substrates underlying neuropsychological functions.

Cognitive abilities in preterm and term-born adolescents

OBJECTIVE

To investigate the influence of a range of prenatal and postnatal factors on cognitive development in preterm and term-born adolescents.

STUDY DESIGN

Woodcock-Johnson III Tests of Cognitive Abilities were used to assess general intellectual ability and 6 broad cognitive abilities in 145 young adolescents aged approximately 12.5 years and born 25-41 weeks gestational age (GA). To study potential links between neurophysiologic and cognitive outcomes, corticomotor excitability was measured using transcranial magnetic stimulation and surface electromyography. The influence of various prenatal and postnatal factors on cognitive development was investigated using relative importance regression modeling.

RESULTS

Adolescents with greater GA tended to have better cognitive abilities (particularly general intellectual ability, working memory, and cognitive efficiency) and higher corticomotor excitability. Corticomotor excitability explained a higher proportion of the variance in cognitive outcome than GA. But the strongest predictors of cognitive outcome were combinations of prenatal and postnatal factors, particularly degree of social disadvantage at the time of birth, birthweight percentile, and height at assessment.

CONCLUSIONS

In otherwise neurologically healthy adolescents, GA accounts for little interindividual variability in cognitive abilities. The association between corticomotor excitability and cognitive performance suggests that reduced connectivity, potentially associated with brain microstructural abnormalities, may contribute to cognitive deficits in preterm children. It remains to be determined if the effects of low GA on cognitive outcomes attenuate over childhood in favor of a concomitant increase in the relative importance of heritability, or alternatively, if cognitive development is more heavily influenced by the quality of the postnatal environment.

The growth of very-low-birth-weight infants at 5 years old in Taiwan

BACKGROUND

The goal of this study was to compare the growth and effect of growth on cognitive performance at 5 years of age of a group of very-low-birth-weight (VLBW) infants and a group of healthy full-term infants.

METHODS

Beginning in 1995, under the sponsorship of the Premature Baby Foundation, the Society of Neonatology, Taiwan, conducted a multicenter follow-up study of VLBW infants in Taiwan. The study enrolled 322 VLBW infants and 103 controls for assessment of growth data and cognitive performance at several time points from birth through to 5 years of age. Growth data were assessed with measurements of weight, height, and head circumference taken at the ages of 6 months, 12 months, 24 months, and 60 months. Cognitive performance was assessed at the age of 5 years. The VLBW infants were regarded as "failed" if a measurement was 2 standard deviations below the mean measurement of the control group. Neonatal and perinatal data had been collected prospectively as part of a longitudinal study. Cognitive performance was assessed using the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-R).

RESULTS

From 6 months to 5 years, VLBW infants had lower weight, height, and head circumference than the controls. Two hundred twenty-four VLBW infants (69.6%) returned for assessment at 5 years old. Of the 224 VLBW infants, complete sets of measurements of weight, height, and head circumference were obtained for 126 cases (56.3%), 127 cases (56.7%), and 106 cases (47.3%), respectively. Of these, 13 patients (10.3%) failed in weight, 11 patients (8.7%) failed in height, and 17 patients (16.0%) failed in head circumference at the age of 5 years. The mean WPPSI-R scores at the age of 5 years for VLBW children were: 94.1 ± 16.4 (performance IQ), 87.2 ± 12.8 (verbal IQ), and 89.5 ± 14.6 (full IQ). All of these values were also lower than those of the control group, with the differences being statistically significant (p < 0.05). The WPPSI-R scores of VLBW children who failed in head circumference were notably lower than those of VLBW children whose head circumference had caught up with that of their peers.

CONCLUSION

The growth of VLBW infants was lower than that of healthy full-term infants through 5 years of age. The cognitive performance for VLBW children was also decreased compared to that of the control group, and there was an association between slower growth and decreased cognitive ability.

Poor postnatal head growth in very preterm infants is associated with impaired neurodevelopment outcome

AIM

To examine the association between neurodevelopmental outcome and head circumference (HC) in a cohort of very preterm infants and in this context to investigate the relevance of suboptimal head size.

METHODS

Somatometric data were obtained at birth, discharge and 3, 12 and 24 months for all infants born in Tyrol <32 weeks gestational age. Growth data are presented as z scores. HC was defined as microcephaly (>2 SD below mean), suboptimal (>1 SD below mean) or normal head size (<1 SD below mean). Neurodevelopmental outcome was quantified at 12 and 24 months using the Bayley Scales of Infant Development II.

RESULTS

The percentage of infants with suboptimal head size increased until the age of 24 months and was related to adverse outcome. The association was strongest between HC at 3 months and psychomotor and mental outcome as quantified using the Bayley Scales of Infant Development.

CONCLUSION

Poor postnatal head growth was common in our study cohort. Both microcephaly and suboptimal head size were associated with impaired neurodevelopmental outcome. Suboptimal head size at 3 months was found to be particularly associated with adverse neurodevelopmental outcome.

Gray matter volumetric MRI differences late-preterm and term infants

Gray matter develops rapidly during the third trimester of pregnancy, which is a critical period for lipid deposition. We measured brain volume in term and late-preterm infants to determine if it is related to disabilities in late-preterm infants. In addition, we measured serum lipid concentrations to investigate the relationship between brain volume and lipid nutrition. Magnetic resonance imaging scans were obtained in 16 late-preterm and 13 term infants. We measured cerebrum, gray matter, and white matter volumes. We performed serum cholesterol, triglyceride (TG), and lipoprotein analyses in cord blood by high-performance liquid chromatography using gel permeation columns to assess lipid nutritional levels. The gray matter volume and percent cerebrum volume of gray matter were significantly smaller in late-preterm infants (p<0.001). Head circumference and cerebrum and white matter volume did not differ between the two groups. Gray matter volume correlated positively with gestational age (r=0.647, p<0.001), head circumference (r=0.688, p<0.001), and high-density lipoprotein (HDL)-TG levels (r=0.496, p=0.006). Late-preterm infants had a normal head circumference and a lower gray matter volume than term infants. Gestational age and head circumference were significantly associated with gray matter volume. Only HDL-TG levels were significantly associated with gray matter volume. HDL-TG might contribute to the transport of fatty acids and gray matter development during the postnatal period. Thus, delayed gray matter development may partly contribute to neurodevelopmental disabilities in late-preterm infants.

Clinical importance of hypothyroxinemia in the preterm infant and a discussion of treatment concerns

PURPOSE OF REVIEW

Survival for the extremely low gestational age neonate (ELGAN; 24-28 weeks) has risen to more than 80%. This extraordinary achievement is tempered by the persistence of cognitive delays and cerebral palsy (CP) affecting nearly one in eight survivors, and requiring subsequent rehabilitative services. A major priority in newborn medicine must be to translate the gains in survival achieved over the past 40 years into gains in healthy survival without the current high frequency of impairments.

RECENT FINDINGS

Transient hypothyroxinemia in ELGANs is strongly associated with lower IQ scores, behavioral abnormalities and CP. Limited evidence suggests the possibility of a benefit from hormone replacement therapy, but the optimal trial has yet to be conducted. A continuous infusion of 4 μg/kg per day thyroxine for 42 days can safely correct transient hypothyroxinemia without markedly lowering thyroid stimulating hormone levels, thus creating a biochemical euthyroid state. Whether this treatment will make an impact on long-term outcomes is not yet known.

SUMMARY

With 25 000 neonates born in less than 28 weeks each year in the USA, the economic impact of the very high rates of cognitive disabilities and related neurological dysfunction in survivors is substantial. The lifetime direct and indirect costs of CP are estimated at US$1 million per person and the costs of mental retardation are even higher. If reversal of transient hypothyroxinemia proves effective in reducing the risks of CP or mental retardation in ELGANs by 30%, we estimate an overall saving of US$ 3 billion per year. There is a pressing need for a phase III trial of thyroid hormone that is of sufficient duration and size to determine whether a clinically important reduction in risk of developmental impairments in ELGANs can be achieved.

Postnatal growth of preterm born children ≤ 750g at birth

BACKGROUND

Extremely low birth weight (ELBW) infants are at risk of impaired postnatal growth. Impaired postnatal growth has been reported to be associated with delayed cognitive and motor development.

AIMS

To describe postnatal growth patterns of appropriate and small for gestational age (AGA and SGA) ELBW children in relation to their cognitive and motor outcome at age 5.5.

STUDY DESIGN

Retrospective cohort study.

SUBJECTS

One hundred one children with a BW ≤ 750g, born between 1996 and 2005 in the University Hospital Utrecht, The Netherlands.

OUTCOME MEASURES

Height (Ht), weight (Wt), occipital-frontal circumference (OFC) at birth, 15 months and 2 years corrected age and 3.5 and 5.5 years. Cognitive and motor outcome at 5.5 years of age, classified as normal (Z-score ≥-1), mildly delayed (-2≤Z-score <-1) or severely delayed (Z-score <-2). AGA (Ht, Wt or OFC at birth ≥-2 SDS) infants were compared with SGA (Ht, Wt or OFC at birth <-2 SDS) infants.

RESULTS

Between birth and 5.5 years catch-up growth in Ht, weight for height (Wt/Ht), Wt and OFC was seen in 72.2%, 55.2%, 28.6% and 68.9% respectively of the SGA infants. For AGA infants we found substantial catch-down growth in Ht (15.4%) and Wt (33.8%). Cognitive and motor outcome was normal in 76.2% and 41.6% of the 101 children. A significantly higher percentage of normal cognitive outcome was found in AGA infants with Wt growth remaining at ≥-2 SDS compared to AGA infants with catch-down growth (83% vs 63%). Next, SGA infants who caught-up in OFC had a higher prevalence of normal cognitive outcome compared to SGA infants who did not catch-up in OFC. Furthermore, a higher percentage of severely delayed motor outcome was found in SGA infants without catch-up growth in Wt compared to SGA infants who caught-up in Wt (61.5% vs 32.2%).

CONCLUSIONS

Catch-up growth in Ht, Wt/Ht and OFC occurred in the majority of the SGA infants with a BW ≤ 750 g, but was less common in Wt. AGA children who remained their Wt at ≥-2 SDS have a better cognitive and motor developmental outcome at 5.5 years of age. Catch-up growth in OFC was associated with a better cognitive outcome at 5.5 years of age.

Very preterm children free of disability or delay at age 2: predictors of schooling at age 8: a population-based longitudinal study

AIM

To study the predictive value of a developmental assessment at 2 years corrected age (CA) for schooling at age 8 in children born very preterm and free of disability or delay; to identify other factors associated with schooling in this population.

METHODS

244 children born before 33 weeks in 1997, part of the population-based EPIPAGE cohort study, free of disability or delay, had their developmental quotient (DQ) evaluated with the Brunet-Lezine scale at 2 years CA. The mental processing composite (MPC) score was evaluated at age 5 with the K-ABC battery. Data on schooling were obtained at age 8 by postal questionnaire. Schooling was considered appropriate if the child was attending age-appropriate grade level in a regular classroom environment without support at school.

RESULTS

Schooling was appropriate for 172 (70%) children. The predictive value of a DQ≥100 for appropriate schooling was 0.80 [0.75;0.85]. In children with a DQ at age 2<100, schooling varied significantly according to their MPC score at age 5 whereas it didn't in children with a DQ≥100. In multivariate analysis, the rate of appropriate schooling was significantly related to global DQ at age 2 (p<0.01), gestational age≥29 weeks (p<0.05), head circumference at age 2 (p<0.05) and mother's educational level (p<0.05).

CONCLUSION

A DQ≥100 cannot be solely used for the prediction of appropriate schooling at age 8. Mother's educational level, gestational age and head circumference at age 2 could be taken account. These factors could be used to individualise follow-up.

Post-natal growth of 157 children born as extremely premature neonates

AIM

With increasing survival rate of extremely premature neonates, their long-term outcomes including growth and risk factors for later disorders need to be considered. We prospectively evaluated anthropometric parameters in children born as extremely premature neonates.

METHODS

Anthropometric parameters were measured at the ages of 2 and 5 years in 72 extremely premature children born between the 22nd and 25 + 6th weeks of gestation (group I) and 85 children born between the 26th and 27 + 6th weeks of gestation (group II).

RESULTS

Although catch-up in the postnatal growth was observed in both groups of children, resulting in growth improvement, the height of the extremely premature children at the ages of 2 and 5 years remains lower (P < 0.01) compared with the control population. A decline in head growth was observed in both groups between the ages of 2 and 5 years, resulting in decrease of standard deviation score (SDS) for head circumference (HC) in comparison with that of the control population, accompanied by an increased number of children with microcephaly, defined as HC < -2 SD. At the age of five, microcephaly was found in 18% of children from group I and 11.7% of children from group II. At the age of 5 years, the waist and hip circumferences and ten skinfolds were not different between both groups of children.

CONCLUSION

Long-term follow-up of extremely premature neonates is important not only to establish their growth patterns but also for risk factors assessment including adiposity for later development of adult-onset diseases.

Early cranial ultrasound lesions predict microcephaly at age 2 years in preterm infants

To assess how well early ultrasound lesions in preterm newborns predict reduced head circumference at 2 years, the investigators followed 923 children born before the 28th week of gestation who were not microcephalic at birth. Six percent of children who had a normal ultrasound scan were microcephalic compared with 15% to 20% who had intraventricular hemorrhage, an echolucent lesion, or ventriculomegaly. The odds ratios (95% confidence intervals) for microcephaly associated with different ultrasound images were intraventricular hemorrhage, 1.5 (0.8-3.0); ventriculomegaly, 3.3 (1.8-6.0); an echodense lesion, 1.6 (0.7-3.5); and an echolucent lesion, 3.1 (1.5-6.2). Ventriculomegaly and an echolucent lesion had very similar low positive predictive values (24% and 27%, respectively) and high negative predictive values (91% and 90%, respectively) for microcephaly. Ventriculomegaly had a higher sensitivity for microcephaly than did an echolucent lesion (24% vs 16%, respectively). Focal white-matter lesion (echolucent lesion) and diffuse white-matter damage (ventriculomegaly) predict an increased risk of microcephaly.

Weight gain in infancy and early childhood is associated with school age body mass index but not intelligence and blood pressure in very low birth weight children

Rates of weight gain in infancy and early childhood can influence later neurocognitive, metabolic and cardiovascular health. We studied the relationship of weight gain during infancy and early childhood to intelligence quotient (IQ), blood pressure (BP) and body mass index (BMI) at age 9 in children born with very low birth weight (VLBW). Sixty-five children born prematurely with VLBW were followed longitudinally and at 9 years IQ, BP and BMI were measured. The mean weight z-scores at birth, neonatal intensive care discharge, 1 year corrected for prematurity, 5 and 9 years were -0.17, -2.09, -1.3, -0.68 and 0.06, respectively. Weight gain during infancy (discharge to 1 year corrected for prematurity) and early childhood (1 year corrected age to 5 years) was expressed as rate of change in weight, rate of change in weight z-score and interval change in weight z-score. In multiple regression analyses that adjusted for race, gender, maternal education, antenatal steroids, birth weight z-score, major intracranial lesions on ultrasound and chronic lung disease, rates of weight gain in infancy and early childhood were predictive of BMI z-score at 9 years, regression coefficients (95% confidence intervals); 0.19 (0.02, 0.36) and 0.37 (0.11, 0.63), respectively, expressed as change in BMI z-score per 10 g/week weight increase. Rates of weight gain were not predictive of systolic BP z-score, Verbal IQ or Performance IQ. In VLBW infants, more rapid weight gain during infancy, and especially early childhood, is associated with higher BMI at school age.

Reader variability in the use of diagnostic terms to describe white matter lesions seen on cranial scans of severely premature infants: the ELGAN study

PURPOSE

To evaluate reader variability of white matter lesions seen on cranial sonographic scans of extreme low gestational age neonates (ELGANs).

METHODS

In 1,452 ELGANs, cranial sonographic scans were obtained in the first and second postnatal weeks, and between the third postnatal week and term. All sets of scans were read independently by two sonologists. We reviewed the use of four diagnostic labels: early periventricular leucomalacia, cystic periventricular leucomalacia, periventricular hemorrhagic infarction (PVHI), and other white matter diagnosis, by 16 sonologists at 14 institutions. We evaluated the association of these labels with location and laterality of hyperechoic and hypoechoic lesions, location of intraventricular hemorrhage, and characteristics of ventricular enlargement.

RESULTS

Experienced sonologists differed substantially in their application of the diagnostic labels. Three readers applied early periventricular leucomalacia to more than one fourth of all the scans they read, whereas eight applied this label to ≤5% of scans. Five applied PVHI to ≥10% of scans, while three applied this label to ≤5% of scans. More than one third of scans labeled cystic periventricular leucomalacia had unilateral hypoechoic lesions. White matter abnormalities in PVHI were more extensive than in periventricular leucomalacia and were more anteriorly located. Hypoechoic lesions on late scans tended to be in the same locations, regardless of the diagnostic label applied.

CONCLUSIONS

Experienced sonologists differ considerably in their tendency to apply diagnostic labels for white matter lesions. This is due to lack of universally agreed-upon definitions. We recommend reducing this variability to improve the validity of large multicenter studies.

Factors associated with small head circumference at birth among infants born before the 28th week

OBJECTIVE

We sought to identify risk factors for congenital microcephaly in extremely low gestational age newborns.

STUDY DESIGN

Demographic, clinical, and placental characteristics of 1445 infants born before the 28th week were gathered and evaluated for their relationship with congenital microcephaly.

RESULTS

Almost 10% of newborns (n = 138), rather than the expected 2.2%, had microcephaly defined as a head circumference >2 SD below the median. In multivariable models, microcephaly was associated with nonwhite race, severe intrauterine growth restriction, delivery for preeclampsia, placental infarction, and being female. The risk factors for a head circumference between <1 and >2 SD below the median were similar to those of microcephaly.

CONCLUSION

Characteristics associated with fetal growth restriction and preeclampsia are among the strongest correlates of microcephaly among children born at extremely low gestational ages. The elevated risk of a small head among nonwhites and females might reflect the lack of appropriate head circumference standards.

Antenatal antecedents of a small head circumference at age 24-months post-term equivalent in a sample of infants born before the 28th post-menstrual week

BACKGROUND

Little is known about the antecedents of microcephaly in early childhood among children born at extremely low gestational age.

AIM

To identify some of the antecedents of microcephaly at age two years among children born before the 28th week of gestation.

STUDY DESIGN

Observational cohort study.

SUBJECTS

1004 infants born before the 28th week of gestation.

OUTCOME MEASURES

Head circumference Z-scores of <-2 and >or=-2, <-1.

RESULTS

Risk of microcephaly and a less severely restricted head circumference decreased monotonically with increasing gestational age. After adjusting for gestational age and other potential confounders, the risk of microcephaly at age 2 years was increased if microcephaly was present at birth [odds ratio: 8.8 ((95% confidence interval: 3.7, 21)], alpha hemolytic Streptococci were recovered from the placenta parenchyma [2.9 (1.2, 6.9)], the child was a boy [2.8 (1.6, 4.9)], and the child's mother was not married [2.5 (1.5, 4.3)]. Antecedents associated not with microcephaly, but with a less extreme reduction in head circumference were recovery of Propionibacterium sp from the placenta parenchyma [2.9 (1.5, 5.5)], tobacco exposure [2.0 (1.4, 3.0)], and increased syncytial knots in the placenta [2.0 (1.2, 3.2)].

CONCLUSIONS

Although microcephaly at birth predicts a small head circumference at 2 years among children born much before term, pregnancy and maternal characteristics provide supplemental information about the risk of a small head circumference years later. Two findings appear to be novel. Tobacco exposure during pregnancy, and organisms recovered from the placenta predict reduced head circumference at age two years.

The ELGAN study of the brain and related disorders in extremely low gestational age newborns

BACKGROUND

Extremely low gestational age newborns (ELGANs) are at increased risk for structural and functional brain abnormalities.

AIM

To identify factors that contribute to brain damage in ELGANs.

STUDY DESIGN

Multi-center cohort study.

SUBJECTS

We enrolled 1506 ELGANs born before 28 weeks gestation at 14 sites; 1201 (80%) survived to 2 years corrected age. Information about exposures and characteristics was collected by maternal interview, from chart review, microbiologic and histological examination of placentas, and measurement of proteins in umbilical cord and early postnatal blood spots.

OUTCOME MEASURES

Indicators of white matter damage, i.e. ventriculomegaly and echolucent lesions, on protocol cranial ultrasound scans; head circumference and developmental outcomes at 24 months adjusted age, i.e., cerebral palsy, mental and motor scales of the Bayley Scales of Infant Development, and a screen for autism spectrum disorders.

RESULTS

ELGAN Study publications thus far provide evidence that the following are associated with ultrasongraphically detected white matter damage, cerebral palsy, or both: preterm delivery attributed to preterm labor, prelabor premature rupture of membranes, or cervical insufficiency; recovery of microorganisms in the placenta parenchyma, including species categorized as human skin microflora; histological evidence of placental inflammation; lower gestational age at delivery; greater neonatal illness severity; severe chronic lung disease; neonatal bacteremia; and necrotizing enterocolitis.

CONCLUSIONS

In addition to supporting a potential role for many previously identified antecedents of brain damage in ELGANs, our study is the first to provide strong evidence that brain damage in extremely preterm infants is associated with microorganisms in placenta parenchyma.