Cognitive profiles of extremely preterm children: Full-Scale IQ hides strengths and weaknesses

Relations between Neurocognitive Function and Visual Acuity: A Cross-Sessional Study in a Cohort of Premature Children

BACKGROUND

Premature children with retinopathy of prematurity (ROP) have been reported to an have increased risk of visual and neurocognitive impairments, yet little is known about whether vision could affect specific neurocognition. This study aimed to clarify the correlations between neurocognition and vision in premature children.

MATERIALS AND METHODS

This is a nonrandomized, cross-sectional, observational study in a pediatric cohort with five groups: (1) full-term (n = 25), (2) prematurity without ROP (n = 154), (3) prematurity with ROP but without treatment (n = 39), (4) prematurity with ROP and with bevacizumab (IVB) treatment (n = 62), and (5) prematurity with ROP and with laser/laser + IVB treatment (n = 20). Neurocognitive function was evaluated by the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) around the age of 4 years. Visual acuity (VA) and refractive errors were tested. Correlations between WPPSI parameters and visual outcomes were analyzed across five groups.

RESULTS

Among the 300 recruited children (mean age = 4.02 + 0.97 years, male = 56.3%), 297 were assessed by WPPSI-IV and 142 were assessed by vision tests. The Full-Scale Intelligence Quotient (FSIQ) index was worse in the premature groups. After adjusting for covariates, seven items, including FSIQ-Index (p = 0.047), fluid-reasoning index (p = 0.004), FR-percentile ranking (p = 0.008), object assembly (p = 0.034), picture concept (p = 0.034), zoo locations (p = 0.014) and bug search (p = 0.020), showed significant differences between groups. The better the best corrected VA (BCVA), the higher the scores on Verbal Comprehension Index (VCI), VCI-PR, and the subtest of information.

CONCLUSIONS

Specific cognitive dysfunctions are related to the BCVA in this large cohort. Subtest performance profiles in WPPSI can be affected by prematurity, ROP treatment, and different ROP treatment. FSIQ is generally lower in premature children and even lower in children with ROP.

Intellectual Development in Mexican Preterm Children at Risk of Perinatal Brain Damage: A Longitudinal Study

Preterm birth accounts for about 10% of births worldwide. Studying risk factors for perinatal brain damage is essential, as findings suggest that almost 20% of disabilities are linked to risks in the early stages of development. This research aimed to study longitudinal changes in intelligence from 6 to 8 years of age in a sample of 39 preterm children with a history of risk of brain damage and a control group of 35 children born at term. The Wechsler Intelligence Scale (WISC-IV) was used to measure cognitive ability at six, seven, and eight years old. The results showed that the preterm group obtained significantly lower scores than the control group. The working memory indicator significantly affected the interaction between age and prematurity. We consider it crucial to expand the knowledge we have about the neurocognitive development of premature infants, both in specific cognitive domains and in age ranges, so that the information obtained can help predict the probability of presenting cognitive alterations from early stages. This, therefore, helps in implementing intervention strategies and programs based on scientific evidence, and their design is complemented by clinical experience and empirical and theoretical knowledge of the different professionals involved in infant cognitive intervention.

Does the Degree of Prematurity Relate to the Bayley-4 Scores Earned by Matched Samples of Infants and Toddlers across the Cognitive, Language, and Motor Domains?

The literature on children born prematurely has consistently shown that full-term babies outperform preterm babies by about 12 IQ points, even when tested as adolescents, and this advantage for full-term infants extends to the language and motor domains as well. The results of comprehensive meta-analyses suggest that the degree of prematurity greatly influences later test performance, but these inferences are based on data from an array of separate studies with no control of potential confounding variables such as age. This study analyzed Bayley-4 data for 66 extremely premature infants and toddlers (<32 weeks), 70 moderately premature children (32-36 weeks), and 133 full-term children. All groups were carefully matched on key background variables by the test publisher during the standardization of the Bayley-4. This investigation analyzed data on the five subtests: cognitive, expressive communication, receptive communication, fine motor, and gross motor. A multivariate analysis of covariance (MANCOVA) assessed for group mean differences across the three subsamples, while controlling for the children's age. Extremely premature children scored significantly lower than moderately premature children on all subtests, and both preterm groups were significantly outscored by the full-term sample across all domains. In each set of comparisons, the cognitive and motor subtests yielded the largest differences, whereas language development, both expressive and receptive, appeared the least impacted by prematurity. A follow-up MANOVA was conducted to examine full-term versus preterm discrepancies on the five subtests for infants (2-17 months) vs. toddlers (18-42 months). For that analysis, the two preterm groups were combined into a single preterm sample, and a significant interaction between the age level and group (full-term vs. preterm) was found. Premature infants scored lower than premature toddlers on receptive communication, fine motor, and cognitive. Neither expressive communication nor gross motor produced significant discrepancies between age groups The findings of this study enrich the preterm literature on the degree of prematurity; the age-based interactions have implications for which abilities are most likely to improve as infants grow into toddlerhood.

Intelligence Quotient (IQ) in school-aged preterm infants: A systematic review

Preterm birth (before 37 weeks of gestational age) is associated with certain risks to child development. The aim of this systematic review was to summarize available and updated empirical evidence on prematurity as a risk factor for cognitive development in school age. Thus, we attempted to identify similarities and differences with the full-term population and to point out possible risk or protective factors among the biological, psychosocial and family variables. The conceptualization and methodology of this review followed the PRISMA recommendations. The search was carried out in Web of Science, Scopus, PsycInfo, and Dialnet databases, in May 2022. The search was limited to journal articles, published between 2012 and 2022, in English and Spanish. Research articles selected were those focused on the intelligence quotient (IQ) of preterm children aged 6-12 years. The review included studies with cross-sectional or longitudinal cohorts, compared to a control group of children born at term or to standardized scales. The quality of evidence of the selected studies was verified with the Mixed Methods Appraisal Tool (MMAT). The initial search identified 1,040 articles. Forty articles met the inclusion criteria and were finally included in this review. These studies involved 5,396 preterm children from 37 different cohorts. Despite the diversity found among the results, in general, total IQ scores were within the normative mean for premature children; however, compared to their full-term peers, these scores were lower. The most studied variables in relation to IQ are perinatal (e.g., gestational age and birth weight) and family (e.g., socioeconomic level and education level of the mother). Recent studies corroborate that premature birth affects cognitive development in school age, and identify associated perinatal and family variables.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=337371; identifier: CRD42022337371.

Neurodevelopmental outcomes of very low birth weight preterms in preschool childhood: a prospective cohort study

BACKGROUND

Preterm birth is a risk factor for a child's neurological development. Preterm children have unusual neurodevelopmental profiles with executive, visual-motor functions, fine and gross motor skills, language and behavior that affect learning. In this study, we analyzed the neurodevelopmental outcomes of a cohort of very low birth weight infants admitted to the Treviso Neonatal Intensive Care Unit (NICU) between 2014 and 2016 and followed up to preschool childhood.

METHOD

This is a prospective cohort study. Infants were followed at birth and after NICU discharge at two- and four-year follow-ups. The two-year assessment was conducted with Bayley III, and at four years with the Wechsler Preschool and Primary Scale of Intelligence - III scales and Movement Assessment Battery for Children - 2.

RESULTS

The cohort consisted of 207 subjects with a mean gestational age of 28.9 weeks, and a mean birth weight of 1097.2 g. At two years of age, children without disabilities were 90 (59.6%), those with minor disabilities 47 (31.1%), and those with major disabilities 14 (9.3%); at four years, 58.4% of children without previous disabilities, presented problems with verbal tests and manual dexterity: aiming, grasping and balance at movement assessment. There was significant alteration in processing speed (p < 0.001). Furthermore, there was a strong correlation between processing speed and manual dexterity (p < 0.001) and between processing speed and aiming and grasping (p = 0.0059).

CONCLUSIONS

We found that more than half the children free of disability at two years, at four years had deficit often involving the oculo-motor coordination and processing speed. These motor profile alterations limit the expression of cognitive abilities and the achievement of expected school performance, thus resulting in behavioral disorders, typical of preterm children. Early professional follow-up could improve the expected educational outcomes.

Correlation Analysis of Attention and Intelligence of Preterm Infants at Preschool Age: A Premature Cohort Study

OBJECTIVE

Developmental delay in neurocognitive function has been reported in premature children. This cohort study prospectively followed preterm infants following birth, and herein we present the four-year longitudinal follow-up data of cognitive development at preschool age and analyze correlated factors.

METHODS

Term and preterm children received regular clinical evaluations and development assessments after birth, and at age 4 ± 1 years, they received the Wechsler-preschool and primary scale of intelligence, Fourth Edition (WPPSI-IV), excluding those with full-scale intelligence quotient < 70. A total of 150 participants received Conners Kiddie Continuous Performance Test (K-CPT), while 129 participants received ophthalmic evaluation. We adopted Chi-square test, ANOVA, and post hoc analysis to compare group differences. Correlations with K-CPT and WPPSI-IV were analyzed using Pearson's correlation.

RESULTS

Group 1 consisted of 25 full-term children, group 2 had 94 preterm children with birth-weight of ≥ 1500 g, and group 3 had 159 preterm children with birth-weight of < 1500 g. Group 1 was the healthiest group and had the best performance in attention and intelligence, while group 3 had the worst physical condition and cognitive performance. The correlation analysis revealed that perinatal factors, including gestational age, birth weight, Apgar scores, and physical conditions, significantly correlated with WPPSI-IV and K-CPT variables. Gender significantly correlated with object assembly of WPSSI-IV and clinical index of K-CPT. Among vision-related variables, best corrected visual acuity correlated most with K-CPT, including clinical index, Omission, and hit reaction time standard error of K-CPT, as well as significantly correlated with information and bug search of WPPSI-IV.

CONCLUSIONS

Preterm children at preschool age still had poorer cognitive performance than full-term children, especially those with birth BW less than 1500 g. Gender and vision are correlated with cognitive deficits. Continuous monitoring with comprehensive assessments is recommended.

Neuropsychological abilities underpinning academic attainment in children born extremely preterm

Children born extremely preterm (EP) have poorer academic attainment than their term-born peers. There is a need to identify the specific cognitive mechanisms that are associated with poor academic attainment in preterm populations to inform the development of intervention strategies. A parallel mediation analysis was conducted with cross-sectional data from 152 EP children (< 27 weeks of gestation) and 120 term-born controls who were assessed at age 11. Mathematics and reading attainment was assessed using the Wechsler Individual Achievement Test 2nd Edition. Controlling for sex and socio-economic status we evaluated the following mediators: verbal working memory, visuospatial working memory, verbal processing speed, attention, and visuospatial processing. These were assessed using subtests from the standardized NEPSY-II test and Wechsler Intelligence Scale for Children-5th Edition. Verbal working memory, visuospatial working memory, visuospatial processing and verbal processing speed, but not attention, were significant independent mediators between EP birth and attainment in reading. No direct relationship between EP birth and reading attainment remained in the mediated model. All five neuropsychological variables mediated the relationship between EP birth and attainment in mathematics, but a direct effect of EP birth on mathematics remained in the mediated model. Together, all five neuropsychological abilities indirectly explained 44% of the variance in reading and 52% of the variance in mathematics. Visuospatial processing was the strongest mediator of both mathematics and reading. Components of executive function, especially visuospatial processing, are important predictors of academic attainment. Interventions to improve visuospatial skills could be trialed in EP populations.

Antenatal steroids and neurodevelopment in 12-year-old children born extremely preterm

AIM

To investigate neurodevelopmental outcome in 12-year-old children born very preterm in relation to perinatal, neonatal and socioeconomic variables. To examine whether previously described positive effects of antenatal steroids on cognition persist at 12 years.

METHODS

Prospective cohort, 78 children with gestational ages 22.7-31.9 weeks, born in 2004-2007 and examined at 12 years of age with cognitive, motor and visual motor integration tasks and compared to an age-matched control group (n = 50). Two preterm subgroups were studied: very preterm children (28-31 gestational weeks, n = 53) and extremely preterm children (22-27 gestational weeks, n = 25).

RESULTS

The preterm children had significantly lower scores on all cognitive, motor and visual motor integration tasks than the controls. Gestational age and maternal education influenced associations differently in the two preterm subgroups. Also, severe retinopathy of prematurity demonstrated strong associations to outcome. In the extremely preterm group, administration of antenatal steroids was associated with better cognition, basic attention, word generation and motor skills.

CONCLUSION

At 12 years of age, very preterm children born in the 2000s still have deficits across several neurodevelopmental domains compared to term-born peers. Administration of antenatal steroids has long-lasting associations to cognition and motor skills in extremely preterm-born children.

Cognitive and academic outcomes of children born extremely preterm

Extremely preterm birth is associated with increased risk for a spectrum of neurodevelopmental problems. This review describes the nature of cognitive and academic outcomes of extremely preterm survivors across childhood and adolescence. Evidence across meta-analyses and large prospective birth cohorts indicate that early developmental difficulties in children born extremely preterm do not resolve with age and are not improving over time despite advancements in neonatal care. While extremely preterm birth confers increased risk of widespread cognitive difficulties, considerable heterogeneity in outcomes is evident across individuals. There is a continued need for high-quality longitudinal studies to understand the developmental progression of cognitive and academic skills following extremely preterm birth, and greater focus on understanding contributing factors that may help to explain the individual variability in cognitive and academic outcomes of extremely preterm survivors.

Extremely low birthweight neonates with phenylketonuria require special dietary management

AIM

Extremely low birthweight (ELBW) neonates require a high protein intake, but this can be challenging in the very rare cases when they also have phenylketonuria (PKU). This is due to a lack of suitable parenteral nutrition or enteral formula. Our aim was to analyse tolerance to phenylalanine in these infants.

MATERIAL

There are approximately 110 000 children born in the Czech Republic each year. A neonatal screening programme from 2005 to 2020 found that 320 neonates had PKU, including 30 premature neonates with a birth weight of less than 2500 g.

RESULTS

This study focused on three neonates who were born with ELBWs of 720, 740 and 950 g, respectively. Phenylalanine levels normalised in ELBW neonates with PKU within 1 week of the introduction of low-phenylalanine parenteral or enteral nutrition. The tolerance to phenylalanine was very high (70-110 mg/kg) in the first months of life, due to a rapid weight gain, but significantly decreased during infancy.

CONCLUSION

Extremely low birthweight neonates with PKU need special dietary management. Regular assessments of phenylalanine are necessary during the first weeks of life to allow prompt dietary adjustments that reflect rapid weight gain and transitory high tolerance to phenylalanine.

Current Challenges Supporting School-Aged Children with Vision Problems: A Rapid Review

Many children have undetected vision problems or insufficient visual information processing that may be a factor in lower academic outcomes. The aim of this paper is to contribute to a better understanding of the importance of vision screening for school-aged children, and to investigate the possibilities of how eye-tracking (ET) technologies can support this. While there are indications that these technologies can support vision screening, a broad understanding of how to apply them and by whom, and if it is possible to utilize them at schools, is lacking. We review interdisciplinary research on performing vision investigations, and discuss current challenges for technology support. The focus is on exploring the possibilities of ET technologies to better support screening and handling of vision disorders, especially by non-vision experts. The data orginate from a literature survey of peer-reviewed journals and conference articles complemented by secondary sources, following a rapid review methodology. We highlight current trends in supportive technologies for vision screening, and identify the involved stakeholders and the research studies that discuss how to develop more supportive ET technologies for vision screening and training by non-experts.