Cerebral MRI findings in a cohort of ex-preterm and control adolescents

Aim: Newborn infants were entered between 1988 and 1993 into a prospective, long-term, follow-up study. We aimed to investigate how the outcome of preterm-born individuals on cerebral magnetic resonance imaging (MRI) compared to that reported on similar cohorts internationally. Methods: The 74 ex-preterm (12.38-17.7 years, 51% girls) and 69 control participants (12.18-16.47 years, 53% girls) underwent a MRI examination on a 1.5T scanner. Two experienced neuroradiologists examined the T1- and T2-weigthed images first independently and then in consensus without knowledge of group adherence. Results: Only 21 (4 controls) of the 143 sets of scans showed any abnormalities. All but one of these were of mild extent. Among the ex-preterm adolescents two showed only incidental findings while the other 15 had either gliosis or white matter loss. Eleven subjects had white matter loss, seven of which had no other abnormalities. Four subjects had gliosis, three of which had no other abnormalities. The extent, severity or frequency of injury was not related to being born small for gestational age. Conclusion: Although the rate of structural abnormalities was higher in the group of adolescents born preterm, this rate was well below that reported from other centres around the world. We attribute this to the minimally invasive neonatal care and to different social structures in Sweden compared to that of other reports on similar cohorts.