If you have not yet given birth, maybe you should post in the pregnancy complications section.
Hydrocephalus is excessive fluid retention in the brain and can cause damage. I'm unsure what procedure they would use for in infants in utero, but you can click the following link for more information.
Every baby has fluid on the brain in the beginning. The occipital and frontal bones are not connected yet at birth. That is called the baby's soft spot. If you damage that part of the babies, skull, lifelong damage will remain.
No worries right now, it will go away