When a child is born prematurely, areas inside the brain (called “lateral ventricles”) that contain many small, thin, and fragile blood vessels are easily injured during the stress of shock of birth and the period of intense care afterward. These vessels burst and bleeding starts within those areas.
Unfortunately, the areas where the bleeding occurs are also those where cerebrospinal fluid forms. The blood may plug the drainage holes, causing the fluid to build within the brain, pushing on surrounding brain tissue, causing further brain damage.
In some cases, the posthemorrhagic hydrocephalus will subside on its own. In other cases, medications and sometimes placing of permanent shunts within the brain to drain the fluid may be necessary.