Intraventricular hemorrhage and its resultant post-hemorrhagic hydrocephalus are significant risk factors for the development of neurodevelopmental delays in preterm infants. The purpose of this study is to determine 1) the incidence of progressive post-hemorrhagic ventricular dilatation (PHVD) in infants with severe intraventricular hemorrhage (IVH), 2) the effect of ventricular dilatation on brain status (cerebral oxygenation, electrical activity, and biomarkers of cerebral damage and repair), and 3) if using ventricular measurements, derived from cranial ultrasound to guide removal of cerebral-spinal fluid through an Omaya reservoir, will help resolve ventricular dilatation and decrease the need for ventriculo-peritoneal (VP) shunt insertion. The hypothesis of this research project is that, by using ventricular measurements to guide the frequency of CSF removal, the rate of VP shunt insertion will be decreased in preterm infants with severe IVH and PHVD. The investigators further hypothesize that cerebral injury, as measured by cerebrospinal fluid (CSF) concentration of biomarkers of neuronal and glial damage and inflammation, will decrease over time with resolution of PHVD.