Change in Volumes and Location of Preterm White Matter Injury over a Period of 15 Years.

OBJECTIVE: To evaluate whether white matter injury (WMI) volumes and spatial distribution, which are important predictors of neurodevelopmental outcomes in preterm infants, have changed over a period of 15 years. STUDY DESIGN: Five hundred and twenty-eight infants born <32 weeks' gestational age from 2 sequential prospective cohorts (cohort 1: 2006 through 2012; cohort 2: 2014 through 2019) underwent early-life (median 32.7 weeks postmenstrual age) and/or term-equivalent-age MRI (median 40.7 weeks postmenstrual age). WMI were manually segmented for quantification of volumes. There were 152 infants with WMI with 74 infants in cohort 1 and 78 in cohort 2. Multivariable linear regression models examined change in WMI volume across cohorts while adjusting for clinical confounders. Lesion maps assessed change in WMI location across cohorts. RESULTS: There was a decrease in WMI volume in cohort 2 compared with cohort 1 (ß = -0.6, 95% CI [-0.8, -0.3], P < .001) with a shift from more central to posterior location of WMI. There was a decrease in clinical illness severity of infants across cohorts. CONCLUSIONS: We found a decrease in WMI volume and shift to more posterior location in very preterm infants over a period of 15 years. This may potentially reflect more advanced maturation of white matter at the time of injury which may be related to changes in clinical practice over time.