What Is Ventriculomegaly?
Fetal ventriculomegaly is a condition in which a fetus's brain ventricles (cavities) are abnormally enlarged. Ventriculomegaly may be mild or severe. Symptoms and treatment vary by its severity.
What Causes Ventriculomegaly?
Ventriculomegaly happens one of two ways:
- The brain tissue around the ventricles is less than it should be because of delayed/failed brain growth or due to brain injury.
- Cerebrospinal fluid (CSF) – which is normally produced in the brain's ventricles and circulates around the brain and spinal cord – abnormally accumulates in the ventricles (a condition known as hydrocephalus).
Symptoms of Ventriculomegaly
After birth, mild ventriculomegaly may not produce any symptoms or signs. If the condition is severe or caused by worsening hydrocephalus (CSF buildup in the brain), your baby may have one or more of these symptoms:
- Full or bulging "soft spot" (fontanel) on the newborn's skull
- Prominent veins in the scalp
- Irritability or unusual sleepiness
- Poor feeding or projectile vomiting
- Abnormally rapid head growth
- Difficulty with eye movement: inability to look upward or constantly staring downward
- Developmental delays
How Is Ventriculomegaly Diagnosed?
Usually, ventriculomegaly in a fetus is first detected during a routine prenatal ultrasound exam during an obstetric visit. Ultrasound can measure the fetal brain's ventricle size. These ultrasound measurements can be repeated during the rest of pregnancy to monitor the ventricle size.
Depending on the size and growth of the ventricles, your doctor may refer you to our Fetal Medicine Institute for further testing to evaluate your baby's condition. Tests may include:
- High-resolution (level II) ultrasound to confirm the diagnosis
- Fetal MRI to help confirm the diagnosis and identify whether associated brain problems are present. This advanced, high-resolution imaging test gives the best information about the underlying cause and the rest of the baby's brain.
Read more about the high-risk prenatal care services at the Fetal Medicine Institute of Children's National.
Treatments for Ventriculomegaly
If your child has mildly enlarged brain ventricles or ventriculomegaly without other complications, the condition may resolve on its own.
When hydrocephalus is more severe or progresses, timely treatment is important. This is because excess CSF buildup can cause pressure on the brain and neurological problems over time.
After birth, our pediatric experts will evaluate your baby to determine whether treatment is needed. The goal of treatment is to provide alternative pathways for the CSF to drain, typically by inserting a ventriculoperitoneal (VP) shunt. Insertion of a VP shunt involves:
- A neurosurgeon inserting one end of a catheter – a long, thin, flexible tube – into the ventricle that is enlarged due to the CSF buildup.
- Placing the other end of the catheter under the skin and extending it down to the chest and abdomen, where the CSF may drain and be absorbed by the abdominal cavity.
The neurologists and neurosurgeons in the Fetal Brain Program at our Fetal Medicine Institute have extensive experience in the management of ventriculomegaly. We provide continuity of care from the early stages of pregnancy, after birth, and across childhood.
Learn more about our Fetal Medicine Institute.