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Medically reviewed by Last updated on Feb 4, 2024.

What is ventriculomegaly (VM)?

VM is a buildup of cerebrospinal fluid (CSF) inside the ventricles of your baby's brain. Ventricles are spaces inside the brain where CSF is naturally produced. CSF is a clear, colorless fluid that protects and cushions your baby's brain. The extra CSF may cause the ventricles to widen and put pressure on your baby's brain. Too much pressure can cause brain swelling and lead to damage. VM can range from mild to severe. VM may go away on its own. Specialists can help you choose the best treatment for VM that is moderate or severe.


What causes VM?

The cause of VM may not be known. VM is usually a sign of an underlying medical condition. VM may be caused by a blockage that affects how your baby's brain produces or absorbs CSF.

What are the signs and symptoms of VM?

With mild VM, your baby may not have any signs or symptoms at birth. Signs and symptoms of severe VM at birth may include any of the following:

How is VM diagnosed?

VM is usually seen during the second trimester of pregnancy. You and your baby may need any of the following:

How is VM treated?

Treatment for VM depends on the cause. Your baby may need treatment for an underlying medical condition. Talk to your baby's healthcare provider or a specialist about treatment options. Your baby may need the following if his or her condition is severe:

When should I call my baby's doctor?

Care Agreement

You have the right to help plan your baby's care. Learn about your baby's health condition and how it may be treated. Discuss treatment options with your baby's healthcare providers to decide what care you want for your baby. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.