Neuropsychological deficits in young adults born small-for-gestational age (SGA) at term

Early childhood parent-reported speech problems in small and large for gestational age term-born and preterm-born infants: a cohort study

OBJECTIVE

(1) To assess if preterm and term small for gestational age (SGA) or large for gestational age (LGA) infants have more parent-reported speech problems in early childhood compared with infants with birth weights appropriate for gestational age (AGA). (2) To assess if preterm and term SGA and LGA infants have more parent-reported learning, behavioural, hearing, movement and hand problems in early childhood compared with AGA infants.

DESIGN

Cohort study.

SETTING

Wales, UK.

PARTICIPANTS

7004 children with neurodevelopmental outcomes from the Respiratory and Neurological Outcomes of Children Born Preterm Study which enrolled 7129 children, born from 23 weeks of gestation onwards, to mothers aged 18-50 years of age were included in the analysis.

OUTCOME MEASURES

Parent-reported single-answer questionnaires were completed in 2013 to assess early childhood neurodevelopmental outcomes. The primary outcome was parent-reported speech problems in early childhood adjusted for clinical and demographic confounders in SGA and LGA infants compared with AGA infants. Secondary outcomes measured were parent-reported early childhood learning, behavioural, hearing, movement and hand problems.

RESULTS

Median age at the time of study was 5 years, range 2-10 years. Although the adjusted OR was 1.19 (0.92 to 1.55) for SGA infants and OR 1.11 (0.88 to 1.41) for LGA infants, this failed to reach statistical significance that these subgroups were more likely to have parent-reported speech problems in early childhood compared with AGA infants. This study also found parent-reported evidence suggestive of potential learning difficulties in early childhood (OR 1.51 (1.13 to 2.02)) and behavioural problems (OR 1.35 (1.01 to 1.79)) in SGA infants.

CONCLUSION

This study of 7004 infants in Wales suggests that infants born SGA or LGA likely do not have higher risks of parent-reported speech problems in early childhood compared with infants born AGA. To further ascertain this finding, studies with wider population coverage and longer-term follow-up would be needed.

Neurocognitive function and associations with mental health in adults born preterm with very low birthweight or small for gestational age at term

Objectives

To assess neurocognitive function in adults born with low birthweight compared with controls and to explore associations between neurocognitive function and psychopathology in these groups.

Methods

In this prospective cohort study, one group born preterm with very low birthweight (VLBW: birthweight <1,500 g, n = 53), one group born small for gestational age at term (SGA: birthweight <10th percentile, n = 63) and one term-born control group (birthweight ≥10th percentile, n = 81) were assessed with neurocognitive tests, diagnostic interviews, and self-report questionnaires at 26 years of age.

Results

The VLBW group scored significantly below the control group on several neurocognitive measures, including IQ measures, psychomotor speed, verbal fluency, aspects of visual learning and memory, attention, social cognition, working memory and fine motor speed. The SGA group consistently scored at an intermediate level between the VLBW and the control group and had significantly lower scores than controls on Performance IQ and psychomotor speed, including switching. In the VLBW group, associations were found between lower spatial working memory and the presence of anxiety disorders, internalizing and attention problems, and autistic traits. Furthermore, lower Full scale IQ was associated with attention problems when adjusting for sex and parental socioeconomic status.

Conclusion

Adults born preterm with VLBW or born term SGA displayed neurocognitive difficulties. Spatial working memory was associated with difficulties with attention, anxiety, and social function of VLBW adults. The finding and its clinical applicability should be further explored.

Sleep Duration and Nocturnal Awakenings in Infants Born with Gestational Risk

OBJECTIVE

Infants born with gestation-related risks (low birth weight (LBW), small for gestational age (SGA), and prematurely born infants) are faced with a cascade of developmental issues. The aim of this study was to investigate whether infants with gestation-related risks have different patterns of parent-reported sleep duration and nocturnal awakenings than children without these risk factors.

METHODS

Information on sleep duration and nocturnal awakenings was obtained by parental report at age 6 and 18 months in the Norwegian Mother and Child Cohort Study, which is a population-based longitudinal pregnancy cohort study conducted at the Norwegian Institute of Public Health. Birth weight and gestational age were obtained from the Medical Birth Registry of Norway. Outcomes were related to birth weight, prematurity, and to being born SGA.

RESULTS

A total of 75,531 mother-child dyads were included. Compared with children without gestational risks, children born SGA and with LBW had shorter sleep duration, whereas children born prematurely had longer sleep duration at both time points. The infants born SGA and with LBW, but not the prematurely born children, had fewer nocturnal awakenings at 6 months, but all had more awakenings at 18 months.

CONCLUSION

Infants with gestation-related risks show distinct sleep patterns. We suggest that sleep assessment is included in the follow-up of high-risk infants. Future studies are needed to investigate the predictive value and functional importance of the sleep patterns for infants with gestation-related risks.

Cognitive Functioning and Academic Achievement in Children Aged 6-8 Years, Born at Term After Intrauterine Growth Restriction and Fetal Cerebral Redistribution

Objective

To determine whether cerebroplacental ratio, an indicator of fetal cerebral redistribution (FCR), predicts adverse results for neurodevelopment in intrauterine growth restriction (IUGR) infants.

Methods

In a cohort of 5,702 infants, 64 were IUGR born at term with FCR. Five were excluded. Of the remainder, 32 presented an abnormal cerebroplacental ratio (IUGR-A) and 27 a normal one (IUGR-B). The controls were 61 appropriate-for-gestational-age children. Cognitive and academic outcomes and the odds ratio of lower academic scores were assessed by multivariate analysis of covariance and logistic regression.

Results

IUGR-A children presented deficits in cognitive functioning and academic achievement in all domains. IUGR-B children presented slight deficits. Suboptimal cognitive functioning in IUGR-A was more marked in working memory. Abnormal cerebroplacental ratio predicted low academic scores in IUGR-A.

Conclusions

FCR is a risk factor for IUGR infants, and cerebroplacental ratio identifies those most severely affected. Intervention programs may produce benefits in early-middle childhood.

Structural Brain Network Reorganization and Social Cognition Related to Adverse Perinatal Condition from Infancy to Early Adolescence

Adverse conditions during fetal life have been associated to both structural and functional changes in neurodevelopment from the neonatal period to adolescence. In this study, connectomics was used to assess the evolution of brain networks from infancy to early adolescence. Brain network reorganization over time in subjects who had suffered adverse perinatal conditions is characterized and related to neurodevelopment and cognition. Three cohorts of prematurely born infants and children (between 28 and 35 weeks of gestational age), including individuals with a birth weight appropriated for gestational age and with intrauterine growth restriction (IUGR), were evaluated at 1, 6, and 10 years of age, respectively. A common developmental trajectory of brain networks was identified in both control and IUGR groups: network efficiencies of the fractional anisotropy (FA)-weighted and normalized connectomes increase with age, which can be related to maturation and myelination of fiber connections while the number of connections decreases, which can be associated to an axonal pruning process and reorganization. Comparing subjects with or without IUGR, a similar pattern of network differences between groups was observed in the three developmental stages, mainly characterized by IUGR group having reduced brain network efficiencies in binary and FA-weighted connectomes and increased efficiencies in the connectome normalized by its total connection strength (FA). Associations between brain networks and neurobehavioral impairments were also evaluated showing a relationship between different network metrics and specific social cognition-related scores, as well as a higher risk of inattention/hyperactivity and/or executive functional disorders in IUGR children.

Small-for-gestation birth exerts a minor additional effect on functional impairment of the auditory brainstem in high-risk babies born at late preterm

OBJECTIVE

To address if small-for-gestational-age (SGA) significantly affects the developing auditory brainstem in late preterm babies with perinatal problems (i.e. high-risk), providing valuable information for management of such babies.

METHODS

SGA and appropriate-for-gestational age (AGA) babies born at 33-36weeks of gestation were studied at term using maximum length sequence brainstem auditory evoked response in response to 91-910/s clicks.

RESULTS

Compared with AGA late preterm babies without perinatal problems (i.e. low-risk), the high-risk SGA babies manifested a significant increase in wave V latency and I-V interval at all 91-910/s clicks, and III-V interval at 455 and 910/s. The amplitude was smaller for wave I at 227 and 910/s, wave III at 910/s and wave V at 227 and 910/s. Compared with low-risk SGA babies, the high-risk SGA babies showed similarly abnormalities. Compared with high-risk AGA babies, the high-risk SGA babies manifested slightly different abnormalities.

CONCLUSIONS

Brainstem auditory response was abnormal in high-risk SGA late preterm babies. The abnormalities, suggesting brainstem auditory impairment, were slightly different from high-risk AGA late preterm babies.

SIGNIFICANCE

SGA birth exerts a minor additional effect on the impaired auditory brainstem in high-risk babies born at late preterm. For these babies, neuroprotective measures should mainly target at associated perinatal problems, although the relatively minor adverse SGA effect cannot be ignored.

Executive function relates to surface area of frontal and temporal cortex in very-low-birth-weight late teenagers

BACKGROUND

Being born with very low birth weight (VLBW; birth weight (BW) ≤1500 g) is associated with increased risk of maldevelopment of the immature brain which may affect neurological functioning. Deficits in attention and executive function problems have been reported in VLBW survivors compared with healthy subjects.

AIMS

The aim of this study was to evaluate attention and executive functions and to relate the clinical test results to cortical morphometry findings in VLBW young adults compared with term-born controls.

STUDY DESIGN

Prospective follow-up study of three year cohorts of VLBW and control children from birth to adulthood.

OUTCOME MEASURES

A comprehensive neuropsychological test battery was administered to 55 VLBW subjects born preterm (mean BW: 1217 g) and 81 term-born controls (mean BW: 3707 g) at age 19-20. Cerebral MRI was successfully obtained in 46 VLBW subjects and 61 controls. The FreeSurfer software package was applied for the cortical analyses based on T1-weighted MRI images.

RESULTS

The VLBW group obtained inferior scores on 15 of the 29 neuropsychological measures assessing attention and executive function and on both the attention and executive function domain scores. We found positive correlations between the executive function domain score and cortical surface area, especially in the antero-medial frontal and the temporal lobes of the brain in the VLBW group.

CONCLUSION

Young adults born with VLBW show deficits in attention and executive function compared with controls. The executive problems were related to smaller cortical surface area in brain regions known to be involved in higher order cognitive functioning.

Brain morphometry and cognition in young adults born small for gestational age at term

OBJECTIVES

To examine brain volumes and cortical surface area and thickness and to relate these brain measures to cognitive function in young adults born small for gestational age (SGA) at term compared with non-SGA control patients.

STUDY DESIGN

This population-based follow-up study at age 20 years included 58 term-born SGA (birth weight <10th percentile, mean: 2915 g) and 81 non-SGA controls (birth weight ≥ 10th percentile, mean: 3707 g). Brain volumes and cortical surface area and thickness were investigated with magnetic resonance imaging, which was successfully obtained in 47 SGA patients and 61 control patients. Cognitive function was assessed using the Wechsler Adult Intelligence Scale, 3rd edition. A subgroup analysis was performed in the SGA group among subjects diagnosed with fetal growth restriction (FGR) based on repeated fetal ultrasound measurements.

RESULTS

The SGA group showed regional reductions in cortical surface area, particularly in the frontal, parietal, and temporal lobes. Total brain volume, cortical gray matter, cerebral white matter, and putamen volumes were reduced in the SGA group compared with control patients, but there were no differences in specific subcortical brain structure volumes when correcting for intracranial volume. Reductions were most pronounced among SGA subjects with FGR. No associations were found between brain measures and IQ measures in either group.

CONCLUSION

Young adults born SGA at term show a global reduction in brain volume as well as regional reductions in cortical surface area. We speculate whether these reductions may be confined to those exposed to FGR. None of the brain measures correlated with cognition.