Fetal (prenatal) hydrocephalus

What it is

Fetal (or prenatal) hydrocephalus is hydrocephalus identified in a developing baby before birth, through prenatal imaging. It reflects enlarged ventricles seen during pregnancy, often discovered when ventriculomegaly is noted on ultrasound.

Understanding Fetal (prenatal) hydrocephalus

Prenatal ultrasound can reveal enlarged ventricles, and fetal MRI can add detail about the brain and the possible cause. Identifying hydrocephalus before birth allows families to learn about the condition, undergo further evaluation (including for associated conditions and genetic causes), and plan for delivery at a center able to provide the needed care. The causes of fetal hydrocephalus — such as aqueductal stenosis, spina bifida, or infections — and the outlook vary widely depending on the underlying cause and any associated findings. Counseling helps families understand the specific situation.

Why it matters

Understanding fetal hydrocephalus helps families see that detecting it before birth allows planning and evaluation, and that the cause and any associated findings — not the diagnosis alone — shape the outlook and care.