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Hearing Screening and Congenital Cytomegalovirus (CMV)

Patient information A-Z

What is congenital CMV?

Cytomegalovirus (CMV) is a common virus which can cause symptoms similar to a cold in adults. However, CMV can sometimes cause more significant symptoms if a baby is exposed to it before they are born. This is called congenital CMV.

Most babies who have congenital CMV are well with no signs of the infection. However, it can cause hearing problems in babies who are otherwise well.

Why is it important to test babies for congenital CMV?

Congenital CMV causes up to 25% of permanent hearing loss in young children. Babies need to be diagnosed and assessed within the first few weeks of life.

What happens next?

If your baby does not have congenital CMV:

If the test is negative, the hearing screening department will send you a letter telling you your baby does not have congenital CMV. You will still need to bring your baby for the formal hearing test as they did not have a clear response on their hearing screen.

If your baby does have congenital CMV:

The hearing screen department will contact you by telephone to arrange appointments, a formal hearing test and a medical review to find out if your baby has any symptoms of congenital CMV. These will be arranged as soon as possible so treatment can be started early if it is needed. The paediatrician will discuss the treatment options with you.

Your baby will be offered follow-up in clinic including regular hearing tests. Most babies with congenital CMV have no health problems.

Is there a problem with my baby’s hearing?

  • Your baby did not have a clear response on their hearing screen and has been referred for a formal hearing test. The formal test may show there is nothing wrong with your baby’s hearing, but it might show that they have a hearing loss.
  • Although there are many causes for hearing loss in babies, one possible cause is congenital CMV. It is best to diagnose congenital CMV early, so we will ask you to consent for your baby to be tested.

What does the CMV test involve?

A small swab (similar to a cotton bud) will be placed gently in your baby’s mouth against the cheek to collect saliva. This will then be sent to a specialist laboratory to test for the virus.

Can you treat congenital CMV?

Doctors have been treating older patients who have CMV with anti-viral medicines for many years. Research studies show that these medicines can also help some babies with congenital CMV. In some cases, the medicine can stop hearing loss getting worse, or may even improve it. At the moment we believe the medicine needs to be given early.

Contacts/Further information

For more information about congenital CMV, please visit See CMV on the NHSconditions website.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151