Intraventricular Hemorrhage in Premature Infants

Four major varieties of intracranial hemorrhage can be recognized in the neonatal period: (1) subdural hemorrhage, (2) primary subarachnoid hemorrhage, (3) intracerebellar hemorrhage, and (4) periventricular-intraventricular hemorrhage.1 Subdural hemorrhage, often related to obstetrical trauma, now is an uncommon lesion in most medical centers. Primary subarachnoid hemorrhage, although very common, is rarely of major clinical importance, because of its venous origin and self-limited course. Intracerebellar hemorrhage, commonly observed at postmortem examination of the small premature infant but rarely documented during life, is of uncertain clinical significance. Periventricular-intraventricular hemorrhage is the most common and serious variety of neonatal intracranial hemorrhage. The enormous importance of this lesion is linked to the remarkable improvements in recent years in neonatal intensive care and, as a consequence, in survival rates for small premature infants. Because periventricular-intraventricular hemorrhage is characteristic of the premature infant (particularly the infant less than approximately 32 weeks gestation), the lesion has reached nearly epidemic proportions in modern neonatal intensive care facilities. INCIDENCE The remarkably high incidence of periventricular-intraventricular hemorrhage is demonstrated dramatically by studies in which premature infants were subjected to computed tomography (CT) scan routinely within the first week of life (Table 1). Thus, 40% to 45% of all such infants exhibited periventricular-intraventricular hemorrhage.2,3