The neuropathology of acquired pre- and perinatal brain injuries.

Acquired pre- and perinatal brain injuries comprise a significant proportion of perinatal neuropathology. They are associated with placental abnormalities, maternal factors, multiple gestations, and preterm labor, as well as with the later development of cerebral palsy and developmental delay. The patterns of perinatal brain injury depend on the etiology (often hypoxic-ischemic) and the timing relative to the development of the fetal nervous system, since the vulnerabilities of gray and white matter differ across postconceptional age and by neuroanatomic site. Nevertheless, characteristic features allow determination of the approximate age and cause of each pattern of injury in the perinatal brain.