Grey and white matter volume changes after preterm birth: A meta-analytic approach

ABSTRACT Objective Lower brain grey matter volumes (GMV) and white matter volumes (WMV) have been reported at single time points in preterm-born individuals. While large MRI studies in the normative population have led to a better understanding of brain growth trajectories across the lifespan, such results remain elusive for preterm-born individuals since large, aggregated datasets of preterm-born individuals do not exist. To close this gap, we investigated GMV and WMV in preterm-born individuals as reported in the literature and contrasted it against individual volumetric data and trajectories from the general population. Study design Systematic database search of PubMed and Web of Science in March 2021 and extraction of outcome measures by two independent reviewers. Individual data on full-term controls was extracted from freely available databases. Mean GMV, WMV, total intracranial volume (TIV), and mean age at scan were the main outcome measures. Results Of 532 identified records, nine studies were included with 538 preterm-born subjects between 1.1 and 28.5 years of age. Reference data was generated from 880 full-term controls between 1 and 30 years of age. GMV was consistently lower in preterm-born individuals from infancy to early adulthood with no evidence for catch-up growth. While GMV changes followed a similar trajectory as full-term controls, WMV was particularly low in adolescence after preterm birth. Conclusions Results demonstrate altered brain volumes after premature birth across the first half of lifespan with particularly low white matter volumes in adolescence. Future studies should address this issue in large aggregated datasets of preterm-born individuals.