what causes hydrocephalus in babies

Hydrocephalus in babies can be caused by a variety of factors, including genetic defects or complications of other disorders. Congenital hydrocephalus, which is present at birth, can be caused by certain health conditions such as spina bifida, or by a brain defect that restricts the flow of cerebrospinal fluid (CSF) . Other possible causes of congenital hydrocephalus include a mutation of the X chromosome, rare genetic disorders, and arachnoid cysts. Hydrocephalus can also develop in babies born prematurely, before week 37 of the pregnancy, due to bleeding in the brain that can block the flow of CSF. Acquired hydrocephalus, which develops in children and adults, is usually the result of an injury or illness that affects the brain. Causes of acquired hydrocephalus can include infection during pregnancy, complications of prematurity, bleeding in the brain, and tumors in the head that block the flow of CSF.