Desenvolvimento cognitivo de prematuros à idade escolar: proposta de modelo hierarquizado para investigação dos fatores de risco

Determinants of preterm birth: proposal for a hierarchical theoretical model

Abstract Preterm birth (PB) is a syndrome resulting from a complex relationship between multiple factors which do not have fully understood relationships and causality. This article discusses a hierarchical theoretical model of PB determinants, considering maternal characteristics such as sociodemographic, psychosocial, nutritional, behavioral and biological aspects, traditionally associated with increased risk of PB. The variables were distributed in six dimensions within three hierarchical levels (distal, intermediate and proximal). In this model, the socioeconomic determinants of the mother, family, household and neighborhood play indirect effects on PB through variables at the intermediate level, which in turn affect biological risk factors at the proximal level that have a direct effect on PB. The study presents a hierarchical theoretical model of the factors involved in the PB determination chain and their interrelationships. Understanding these interrelationships is an important step in trying to break the causal chain that makes some women vulnerable to preterm birth.

Determinants of preterm birth: proposal for a hierarchical theoretical model

Preterm birth (PB) is a syndrome resulting from a complex relationship between multiple factors which do not have fully understood relationships and causality. This article discusses a hierarchical theoretical model of PB determinants, considering maternal characteristics such as sociodemographic, psychosocial, nutritional, behavioral and biological aspects, traditionally associated with increased risk of PB. The variables were distributed in six dimensions within three hierarchical levels (distal, intermediate and proximal). In this model, the socioeconomic determinants of the mother, family, household and neighborhood play indirect effects on PB through variables at the intermediate level, which in turn affect biological risk factors at the proximal level that have a direct effect on PB. The study presents a hierarchical theoretical model of the factors involved in the PB determination chain and their interrelationships. Understanding these interrelationships is an important step in trying to break the causal chain that makes some women vulnerable to preterm birth.

Cognitive performance of premature infants: association between bronchopulmonary dysplasia and cognitive skills. Cross-sectional study

CONTEXT AND OBJECTIVE:

Children born prematurely often have worse cognitive performance than those born at term regarding skills such as memory, attention and processing speed. Bronchopulmonary dysplasia may compromise cognitive development. The aims here were: a) To describe the cognitive performance of preterm infants with very low birth weight; b) To investigate its association with bronchopul-monary dysplasia adjusted for sociodemographic, neonatal and post-neonatal factors.

DESIGN AND SETTING:

Cross-sectional study developed in a public tertiary-care hospital.

METHODS:

To evaluate cognition among 112 children, we applied an intelligence scale (Wechsler scale). The average scores for children with and without bronchopulmonary dysplasia were compared across the fve domains of the scale. Associations with bronchopulmonary dysplasia were investigated for domains that showed signifcant diferences between the two groups. Associations between exposure and outcome were estimated via multivariate logistic regression.

RESULTS:

There were no diferences in averages for the full-scale intelligence quotient, verbal intelligence quotient, performance intelligence quotient and general language composite domains. The processing speed quotient was the only domain that presented a signifcant diference between the two groups (P = 0.02). Among the children with bronchopulmonary dysplasia, low full-scale intelligence quotient was observed in 28.1%. In the multivariate analysis, bronchopulmonary dysplasia (odds ratio: 3.1; 95conf-dence interval: 1.1-8.7) remained associated with the outcome of processing speed quotient.

CONCLUSION:

Bronchopulmonary dysplasia was an independent risk factor for alteration of the processing speed quotient.

Relação entre as habilidades auditivas no primeiro ano de vida e o diagnóstico de linguagem em prematuros

RESUMO Objetivo: verificar se há relação entre as habilidades auditivas no primeiro ano de vida e o diagnóstico de linguagem entre os 2 e 4 anos de idade em crianças nascidas pré-termo com peso abaixo de 2000 gramas. Métodos: foram selecionados um grupo de 54 crianças com emissões otoacústicas evocadas por estímulos transientes presentes nos primeiros três meses, com avaliação audiológica comportamental entre os 6 e 18 meses e avaliação de linguagem entre os 2 e 4 anos de idade. Resultados: não foram observadas diferenças estatisticamente significantes entre a ocorrência de reflexo cócleo palpebral e a habilidade de localização sonora entre 6 e 18 meses com resultado da avaliação de linguagem.Em relação à habilidade de reconhecimento de ordens verbais entre os 12 e 18 meses foi observada diferença estatisticamente significante.Crianças que apresentam reconhecimento de ordens verbais alterado entre 12 e 18 meses tem 12,25 vezes mais chances de apresentar linguagem alterada entre os 2 e 4 anos. Conclusão: existe uma relação entre o reconhecimento de ordens verbais alterado entre 12 e 18 meses e a alteração no resultado da avaliação de linguagem entre os 2 e 4 anos.

Breast milk supplementation and preterm infant development after hospital discharge: a randomized clinical trial

OBJECTIVES

To assess the effect of maternal breast milk supplementation on the development of exclusively breast-fed very low birth weight preterm infants at 12 months of corrected age.

METHODS

A randomized clinical trial with 53 infants followed-up after discharge from the neonatal unit until a corrected gestational age of 12 months. Newborns in the intervention group were breastfed exclusively with maternal milk and received 2g of a multinutrient supplement (Pré-Nan(®), Nestlé, Vevey, Switzerland) added to expressed breast milk twice a day until a corrected age of 4-6 months. The control group was exclusively breastfed without supplementation. After monthly follow-up, developmental assessment was performed using the Bayley III Scale.

RESULTS

There was no statistically significant difference on the Bayley III Scale between the intervention and control groups in any of the assessed domains: motor, cognitive, and communication. However, scores in the three domains were always higher in the group that received the supplement. There were a similar number of cases of developmental delay in both groups: seven (28%) in the group that received the supplement and nine (33.3%) in the group that was exclusively breastfed.

CONCLUSIONS

The results failed to show an association between post-discharge multinutrient supplementation and development in the assessed infants.

Preterm children have unfavorable motor, cognitive, and functional performance when compared to term children of preschool age

OBJECTIVE

to compare the motor coordination, cognitive, and functional development of preterm and term children at the age of 4 years.

METHODS

this was a cross-sectional study of 124 four-year-old children, distributed in two different groups, according to gestational age and birth weight, paired by gender, age, and socioeconomic level. All children were evaluated by the Movement Assessment Battery for Children - second edition (MABC-2), the Pediatric Evaluation of Disability Inventory (PEDI), and the Columbia Mental Maturity Scale (CMMS).

RESULTS

preterm children had worse performance in all tests, and 29.1% of the preterm and 6.5% of term groups had scores on the MABC-2 indicative of motor coordination disorder (p=0.002). In the CMMS (p=0.034), the median of the standardized score for the preterm group was 99.0 (± 13.75) and 103.0 (± 12.25) for the term group; on the PEDI, preterm children showed more limited skill repertoire (p=0.001) and required more assistance from the caregiver (p=0.010) than term children.

CONCLUSION

this study reinforced the evidence that preterm children from different socioeconomic backgrounds are more likely to have motor, cognitive, and functional development impairment, detectable before school age, than their term peers.

Habilidades comunicativas de crianças prematuras e prematuras extremas

Objetivo comparar o desempenho das habilidades comunicativas, de crianças nascidas prematuras, prematuras extremas e típicas de idade cronológica entre dois e três anos. Métodos participaram do estudo 72 crianças distribuídas em quatro grupos: 20 prematuros (GE-I), 16 prematuros extremos (GE-II) e 36 crianças com desenvolvimento típico (GC-I e GC-II), de idade cronológica entre dois a três anos. Houve pareamento quanto à idade cronológica e sexo. A avaliação constou da aplicação do Protocolo de Anamnese e Observação do Comportamento Comunicativo. O tratamento estatístico constou do Teste “t” Student e do Teste de Mann-Whitney (p ≤ 0,05). Resultados na comparação entre os grupos de prematuros e típicos (GE-I e GC-I e GEII e GC-II), quanto às habilidades comunicativas verificou-se diferenças significantes, apesar da heterogeneidade no desempenho dos prematuros e prematuros extremos. Na comparação entre os prematuros (GE-I e GE-II) não foram observadas diferenças significantes, entretanto, GE-I obteve desempenho superior em todas as categorias, exceto para a categoria uso de gestos. As categorias de menor ocorrência para GE-I foram: respeitar troca de turno, participar e manter atividade dialógica. Para o GE-II foram: participar e manter atividade dialógica, realizar ordens complexas, iniciar e respeitar troca de turno, funções de informar, oferecer e produzir frases. Conclusão houve diferenças significantes no desempenho comunicativo das crianças prematuras e prematuras extremas, quanto comparadas às crianças típicas, mas não houve diferenças significantes na comparação entre os prematuros. Apesar dos resultados indicarem que os grupos de prematuros tendem ao atraso no desenvolvimento das habilidades comunicativas, os grupos não demonstraram ser homogêneos.

Risk factors for cognitive impairment in school-age children born preterm: application of a hierarchical model

The purpose was to analyze factors associated with cognitive impairment in very low birth weight (VLBW) children born preterm. A prospective cohort of 65 VLBW children was assessed at the age of eight years using the Wechsler Intelligence Scale for Children. A model for the relationship of variables with the cognitive impairment outcome attributed hierarchical levels: distal (socioeconomic variables), intermediate I and II (perinatal and neonatal variables, post-neonatal variables) and proximal (child health and psychosocial stimulation). A multivariate logistic regression was performed. In the multivariate hierarchical logistic regression, the maternal education (OR=0.77, 95%CI 0.63-0.94) and number of prenatal visits (OR=0.73, 95%CI 0.54-0.99) showed a protective association, but the male (OR=7.3, 95%CI 1.54-35.3) was associated with worse results. The VLBW children cognitive performance in the age of eight years benefits from more educated mothers, better prenatal care, and the baby gender as female.