A systematic review of structural brain differences in school-aged children born preterm

Preterm birth (<37 weeks' gestation) is commonly associated with adverse developmental outcomes, many of which correlate with structural brain differences. Differences in brain structure exist between preterm and term-born neonates/babies at term-equivalent age; however, it remains to be determined whether these differences persist in childhood. Two databases, EMBASE and Ovid MEDLINE, were searched to identify all publications using magnetic resonance imaging (MRI) to measure differences in brain structure between preterm and term-born children at 6-10 years old and associated perinatal risk factors. A risk of bias assessment was performed using the ROBINS-E tool. 23 articles were included that reported MRI data from prospective, longitudinal cohort studies. Preterm children showed smaller global and regional tissue volumes and altered white matter microstructure compared to term-born controls. These associations were more pronounced for those born at a lower gestational age and in the presence of perinatal brain injury. Across studies, structural brain differences had varied associations with neurodevelopmental outcomes. Furthermore, this review highlights that there is a clear lack of prospective, longitudinal studies reporting on the association between preterm birth and MRI differences at school age.