However, it is particularly common in premature infants or those of very low birth weight. The cause of IVH in premature infants, unlike that in older infants, children or adults, is rarely due to trauma. Instead it is thought to result from changes in perfusion of the delicate cellular structures that are present in the growing brain, augmented by the immaturity of the cerebral circulatory system, which is especially vulnerable to hypoxic ischemic encephalopathy. The lack of blood flow results in cell death and subsequent breakdown of the blood vessel walls, leading to bleeding. While this bleeding can result in further injury, it is itself a marker for injury that has already occurred. Most intraventricular hemorrhages occur in the first 72 hours after birth. The risk is increased with use of extracorporeal membrane oxygenation in preterm infants. Congenital cytomegalovirus infection can be an important cause. Mechanism
Diagnosis
Diagnosis can be confirmed by the presence of blood inside the ventricles on CT. Infants
In term and preterm infants with IVH, the amount of bleeding varies. IVH is often described in four grades:
Grade I - bleeding occurs just in the germinal matrix
Grade II - bleeding also occurs inside the ventricles, but they are not enlarged
Grade III - ventricles are enlarged by the accumulated blood
Grade IV - bleeding extends into the brain tissue around the ventriclesGrades I and II are most common, and often there are no further complications. Grades III and IV are the most serious and may result in long-term brain injury to the infant.
After a grade III or IV IVH, blood clots may form which can block the flow of cerebrospinal fluid, leading to increased fluid in the brain (hydrocephalus). Prevention
Head positioning in very preterm infants has been suggested as an approach to prevent germinal matrix haemorrhage; however, further research is required to determine the effectiveness at reducing mortality and the most appropriate positioning technique. Approaches include bed tilting, supine mid-line head positioning, supine head rotation 90 degrees, prone mid-line head positioning, head tiling. Treatment
Treatment focuses on monitoring and should be accomplished with inpatient floor service for individuals responsive to commands or neurological ICU observation for those with impaired levels of consciousness. Extra attention should be placed on intracranial pressure (ICP) monitoring via an intraventricular catheter and medications to maintain ICP, blood pressure, and coagulation. In more severe cases an external ventricular drain may be required to maintain ICP and evacuate the hemorrhage, and in extreme cases an open craniotomy may be required. In cases of unilateral IVH with small intraparenchymal hemorrhage the combined method of stereotaxy and open craniotomy has produced promising results. Infants
There have been various therapies employed into preventing the high rates of morbidity and mortality, including diuretic therapy, repeated lumbar puncture, streptokinase therapy  and a combination novel intervention called DRIFT (drainage, irrigation and fibrinolytic therapy). More research is required, in the form of high quality randomized controlled trials, to determine the safety, dosing, and effectiveness of prophylactic heparin and antithrombin treatment for preterm neonates.