Prematurity, postmaturity, and destructive lesions in utero.

Central nervous system (CNS) lesions resulting from hypoxia-ischemia (H-1) during gestation and the perinatal period, and from intrapartum trauma form the subjects of this review. Whereas mechanical factors are primarily responsible for the traumatic lesions, a wide spectrum of complex physiologic disturbances and pathologic sequelae are associated with H-1. CNS damage most commonly occurs among infants born prematurely, term infants of high risk mothers, and those who suffer severe cardiorespiratory problems. Since brain damage can occur in utero, a newborn may harbor already well-established brain lesions at a time when adverse circumstances again produce additional insults. Thus, lesions of various ages ~ay coexist. Moreover, intrapartum complications tend to be more common in brain-damaged fetuses whether such damage is of a developmental or acquired etiology (1). The clinician, therefore, should resist the strong but simplistic temptation to assume that neurologic impairment in the newborn is necessarily a consequence of intrapartum H-1. The current imaging methods of evaluating the brain of the pediatric patient injured by a H-1 or intrapartum traumatic event are: ultrasound (24); computed tomography (CT) (5-8); and magnetic resonance (MR) imaging (9-15). The imaging findings of representative examples of the major brain insults are shown in the figures.