Microstructural alterations in association tracts and language abilities in schoolchildren born very preterm and with poor fetal growth.

BACKGROUND: Prematurity and perinatal risk factors may influence white matter microstructure. In turn, these maturational changes may influence language development in this high-risk population of children. OBJECTIVE: To evaluate differences in the microstructure of association tracts between preterm and term children and between preterm children with appropriate growth and those with fetal growth restriction and to study whether the diffusion tensor metrics of these tracts correlate with language abilities in schoolchildren with no severe neurological impairment. MATERIALS AND METHODS: This study prospectively followed 56 very preterm children (mean gestational age: 28.7 weeks) and 21 age- and gender-matched term children who underwent diffusion tensor imaging at a mean age of 9 years. We used automated probabilistic tractography and measured fractional anisotropy in seven bilateral association tracts known to belong to the white matter language network. Both groups participated in language assessment using five standardised tests at the same age. RESULTS: Preterm children had lower fractional anisotropy in the right superior longitudinal fasciculus 1 compared to term children (P < 0.05). Preterm children with fetal growth restriction had lower fractional anisotropy in the left inferior longitudinal fasciculus compared to preterm children with appropriate fetal growth (P < 0.05). Fractional anisotropy in three dorsal tracts and in two dorsal and one ventral tract had a positive correlation with language assessments among preterm children and preterm children with fetal growth restriction, respectively (P < 0.05). CONCLUSION: There were some microstructural differences in language-related tracts between preterm and term children and between preterm children with appropriate and those with restricted fetal growth. Children with better language abilities had a higher fractional anisotropy in distinct white matter tracts.

Antenatal and neonatal risk factors in very preterm children were associated with language difficulties at 9 years of age.

AIM: This Finnish study compared language and reading abilities between schoolchildren born at a very low gestational age (VLGA) of <32 weeks and at term and analysed any associations between antenatal and neonatal risk factors and language skills in the VLGA group. METHODS: We prospectively followed 76 children born at a VLGA and 50 children born at term when they reached a mean age of 9.0 (8.1-10.0) years. They attended mainstream schools and had no severe neurosensory disabilities. Receptive language ability, rapid naming and word reading were evaluated using standardised tests. RESULTS: Children in the VLGA group had lower scores for receptive language abilities (median 55.0 vs. 57.0, p = 0.01) and word reading (mean 4.4 vs. 5.1, p = 0.03) than the children in the term group. In the VLGA group, foetal growth restriction was associated with lower scores for rapid naming, early intraventricular haemorrhage was associated with poor word reading and respiratory distress syndrome was associated with poor rapid naming (p < 0.05). CONCLUSION: Schoolchildren born at a VLGA had more difficulties with receptive language abilities and word reading than children born at term. Foetal growth restriction and early neonatal morbidities were associated with language difficulties.