Hemorrhages in brain parenchyma and ventricles in preterm infants tend to be grouped as one entity. To help determine whether these hemorrhages should be viewed as one or more entities, we compared the risk profiles of 3 groups of hemorrhages defined by location and time of occurrence: early germinal matrix hemorrhage (GMH), late GMH, and late peri/intraventricular hemorrhage excluding GMH. These 3 groups were determined to have sufficient differences in various risk factors to warrant separate epidemiologic study.