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Who is at risk of CMV?
CMV, or Cytomegalovirus, is a common virus that can infect people of all ages. Most healthy adults and children will have no signs or symptoms and no long-term effects. However, it can pose serious problems to unborn babies if a woman catches CMV during pregnancy, particularly if this happens in early pregnancy. Some babies infected in this way (known as congenital CMV, when the infection is passed from mother to baby across the placenta) will go on to have lifelong health problems such as hearing loss and developmental difficulties.
To find out more, visit our page: 'Making Decisions in Congenital Cytomegalovirus Infection'.
How do I catch CMV?
CMV is spread from one person to another by close and prolonged contact with bodily fluids such as saliva, urine, blood, faeces, tears, breast milk, semen and cervical secretions.
How do I know if I had CMV during pregnancy?
Most healthy children and adults infected with CMV have no symptoms and may not even know that they have been infected. Others may develop a mild illness; symptoms may include fever, sore throat, rash and fatigue. A blood test can tell if you have an active CMV infection or have had a previous infection. Doctors can diagnose a maternal primary CMV infection (catching CMV for the first time) by testing for CMV antibodies to make an estimate of the likely timing of CMV infection. These results will be interpreted by a virologist, as they are not always straightforward.
How might congenital CMV affect my baby?
Symptoms of congenital CMV in babies are variable. Most babies born with congenital CMV will have no signs or symptoms at all and will not develop any problems as they grow older. Others may have no obvious signs at birth, but around 15% may go on to develop hearing loss over time. Some children will be born with obvious symptoms of congenital CMV and around half of these children will have one or more long-term impairments. These may include hearing loss, cerebral palsy, seizures, ADHD, autism, developmental differences and learning delays, feeding issues or visual or sensory impairment.
Overall, around one in every four children born with the virus will have long-term problems such as hearing loss or developmental disabilities due to the infection.
How is congenital CMV diagnosed?
If there is a possibility that your baby has congenital CMV (i.e. you have been diagnosed with a CMV infection in pregnancy, your baby has failed the newborn hearing screening test or your baby has other signs of congenital CMV infection) your baby’s doctor will test to confirm a diagnosis of congenital CMV. This will involve looking for the virus in your baby’s bodily fluids (urine, saliva or blood). If the CMV virus is detected in these samples before three weeks of age, this confirms congenital CMV infection.
Can congenital CMV be diagnosed later than three weeks of age?
If your child tests positive for the CMV virus when they are more than three weeks old, it can be helpful to test the sample of blood that is collected from all babies in the UK when they are a few days old. This sample is called a Newborn Blood Spot. A positive result will confirm that the infection was caught before birth (a congenital infection). However, this test is not perfect, in that it does not pick up all cases of CMV infection (it picks up about 80%). Therefore, a negative result cannot fully rule out congenital infection.
What will happen after diagnosis of congenital CMV?
The following information outlines the investigations, treatment and follow up required after a diagnosis of congenital CMV is made. This may vary slightly between hospitals. Your doctor will be able to advise you of any differences.
Investigation of organ involvement
This will take place in the few weeks after diagnosis.
| Full body count and liver function tests | Congenital CMV can sometimes cause a reduction in the number of red blood cells, white blood cells or platelets as well as inflammation of the liver (hepatitis). |
|---|---|
| Brain scan | Congenital CMV can cause some distinctive changes to the brain. A brain scan can help doctors to see whether the brain has been affected by the virus and consider whether treatment with anti-viral medication is appropriate. In some cases, it can help doctors to identify children who may be most at risk of developmental or hearing problems in the future, though it is difficult to determine outcomes accurately in this way. The doctor will decide on the most appropriate kind of scan (ultrasound, or MRI, or in some cases both). |
| Hearing test | Hearing loss is one of the most common symptoms of congenital CMV. This test will be more detailed than the hearing screen carried out on all babies at birth and carried out by an audiologist. Hearing loss related to CMV infection may be present at birth, but can also develop throughout early childhood. |
| Eye test | This is to check for any inflammation or scarring on the retina (the light sensitive layer of tissue in the back of the eye). Some children may also have visual impairment caused by a brain problem rather than an eye problem. |
Treatment decision
This will be a decision made by a paediatric doctor with expertise in infectious diseases.
The potential benefits and risks of treatment will be explained at this time.
Treatment
- This will be oral valganciclovir liquid twice daily for six months.
- The dose will increase monthly based on the weight of your baby.
- Your baby will have blood test monitoring for medication side effects on week two, week four and then monthly during treatment.
No treatment
Follow up is still important, particularly of hearing.
Follow up appointments
| Specialty | Follow up - treatment | Follow up - no treatment |
|---|---|---|
| Paediatric team, UCLH | Monthly while on treatment, then annually until five years | Annually until five years |
| Neurodevelopment, UCLH | At birth, three months, six months, 12 months and two years of age | At birth, three months, six months, 12 months and two years of age |
|
Ophthalmology, locally |
As directed by Ophthalmology team | As directed by Ophthalmology team |
| Audiology, locally |
Three monthly for the first year Six monthly between one to three years Annually between three to six years |
Three monthly for the first year Six monthly between one to three years Annually between three to six years |
Contact details
Office Hours (Mon-Fri 9am to 5pm): 07970 274 109 - Paediatric Infectious Disease CNS
Urgent Out of Hours Queries: 07803 853 567 - Consultant Hotline
UCLH Switchboard: 020 3456 7890
Email: uclh.
Some of this information has been adapted from the CMV Action website.
Page last updated: 29 October 2024
Review due: 01 October 2026