The near-term (late preterm) human brain and risk for periventricular leukomalacia: a review

Historically the major focus in neonatal neurology has been on brain injury in premature infants born less than 30 gestational weeks. This focus reflects the urgent need to improve the widely recognized poor neurological outcomes that occur in these infants. The most common underlying substrate of cerebral palsy in these premature infants is periventricular leukomalacia (PVL). Nevertheless, PVL also occurs in near-term (late preterm), as well as term, infants, as documented by neuroimaging and autopsy studies. In both very preterm and late preterm infants, gray matter injury is associated with PVL. In this review, we discuss the cellular pathology of PVL and the developmental parameters in oligodendrocytes and neurons that put the late preterm brain at risk in the broader context of brain development and injury close to term. Further research is needed about the clinical and pathologic aspects of brain injury in general and PVL in particular in late preterm infants to optimize management and prevent adverse neurological outcomes in these infants that, however subtle, may be currently underestimated.