Cytomegalovirus (CMV) is a common virus that is usually harmless. Sometimes it causes problems in babies if you catch it during pregnancy (congenital CMV).
Once you have the virus, it stays in your body for the rest of your life.
Your immune system usually controls the virus and most people do not realise they have it.
CMV is mainly spread through close contact with someone who already has CMV. It can be passed on through body fluids including saliva, blood and urine.
CMV can only be passed on when it is "active". This is when:
Pregnant women can pass an "active" CMV infection on to their unborn baby. This is known as congenital CMV.
Some people get flu-like symptoms the first time they catch CMV, including:
If you do have symptoms, they normally get better on their own within about 3 weeks.
If your GP is worried about your or your babies' health they can arrange tests to find out what's causing your symptoms.
CMV that is not causing symptoms does not need any treatment.
There's currently no treatment for CMV in pregnancy and in most cases the virus does not cause any problems for your baby.
Antiviral medicine can be used to treat:
Treatment should help to weaken the virus and reduce the chance of serious problems – but it does not cure CMV infection.
Babies born with congenital CMV need to stay in hospital until the antiviral treatment finishes.
The best way to reduce the risk of catching CMV during pregnancy is with some simple hygiene measures:
There's currently no vaccine for CMV.
Pregnant women who work closely with children or already have a young family are more at risk of catching CMV.
UK charity CMV Action provides help and support if you or your child are diagnosed with CMV