When growing up I remember hearing a woman had baby with water on the brain. What was that? It died

Hydrocephalus. Build up of cerebrospinal fluid (CSF) in the brain causing swelling, pushing the brain up against the skull and damaging the brain tissue. CSF surrounds the brain and spinal cord and cushions the brain. Genetic defects or infections during pregnancy; meningitis/encephalitis, bleeding in the brain-esp if premie, injuries, tumors or trama are possible causes.