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Ventriculomegaly diagram

What is the problem?

During your recent ultrasound examination we have found that your baby has an enlargement of a part of the brain called the atrium or lateral ventricle. There is one ventricle in each half of the brain. This area of the brain produces fluid that normally circulates around the brain and spinal cord. This collection of fluid normally measures less than 10mm at 20 weeks.

What does this mean?

We see this appearance in about 1 in every 250 pregnancies at 20 weeks. It can be a normal variation or associated with viral infection or blood clotting problems. We can arrange for a blood test to be taken from you to exclude these problems. The size of the ventricles may increase further in pregnancy and we know this can be associated with developmental delay in the baby. Ventriculomegaly can also be associated with an underlying chromosomal condition such as Downs Syndrome. You may wish to know for certain whether your baby has a chromosomal problem and this would involve an amniocentesis or chorionic villus sampling. Both of these tests carry a small risk of miscarriage (occurs in about 1 in 100).

What happens next?

You will be given the opportunity to talk to a fetal medicine midwife. You will also be offered a scan appointment in the fetal medicine department. The fetal medicine consultant will discuss with you the need for further scans. Such as a special MRI on the baby’s brain for more detailed look followed by a fetal medicine appointment to review the results.

Useful information

For further details contact the fetal medicine midwives on 01223- 216185, or 01223-245151 and ask for bleep 156-2053.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151