Rubella (German measles) is usually a mild illness. However, if you are pregnant and catch rubella, it can cause serious damage to your unborn child. Before your first pregnancy you should have a blood test to check if you are immune to rubella. If you are not immune, you can be immunised before becoming pregnant.
What is rubella?
Rubella (German measles) is an infection caused by the rubella virus. It is usually a mild illness causing a rash, sore throat and swollen glands. It occurs most commonly in young children but can affect anyone.
Rubella is now uncommon in the UK as a result of the rubella immunisation. See separate leaflet called MMR Immunisation for more details.
What is the congenital rubella syndrome?
If you are pregnant and have rubella (German measles) in the first few months of pregnancy, there is a high chance that the virus will cause severe damage to your developing baby. The virus affects the developing organs and the baby may be born with serious disability - the congenital rubella syndrome. Complications of congenital rubella syndrome include cataracts, deafness, and heart, lung and brain abnormalities. Having rubella infection in the first three months of pregnancy also increases your risk of having a miscarriage.
The risks of your baby developing congenital rubella syndrome are greatest in the first 16 weeks of your pregnancy. The risk is highest in the first 12 weeks of pregnancy. The risk is much lower if you are more than 20 weeks pregnant.
Note: congenital rubella syndrome is extremely rare in the UK.
Before you become pregnant
You should have a blood test before you become pregnant. The blood test checks for antibodies in your blood to show that you are immune to rubella (German measles).
- Children in the UK are immunised against rubella as part of the routine childhood immunisation programme. However, in an extremely small number of children, the immunisation does not work well. In these children, when they become adults, their body does not have enough antibodies to protect against rubella.
- The only way to check whether you are immune is to have the blood test.
- This blood test may be offered in routine well woman checks given to younger women who have not yet become pregnant. If you have not had a test, your practice nurse can arrange for this to be done.
- In particular, women who have come to the UK from overseas may not have been immunised and are then at risk of having a baby with congenital rubella syndrome.
- If the blood test shows that you are not immune, you should be immunised (see separate leaflet called MMR Immunisation).
When you are pregnant
One of the routine blood tests which is taken in early pregnancy checks for rubella (German measles) antibodies. You will be offered this test in subsequent pregnancies also:
- In most women the test is positive for antibodies, which means that you are immune.
- If your test is negative (no antibodies), you are at risk if you come into contact with rubella. You should keep away from people who might have rubella. Once your baby is born, you should be immunised to protect against rubella in future pregnancies.
Contact with rubella during your pregnancy
- If you are pregnant and come into contact with someone with rubella (German measles), you should check your rubella status. Your midwife or doctor will normally have a record of this (from the blood test that was taken early in your pregnancy) if you do not know. Most women are immune due to previous immunisation and will not develop rubella. No further action is needed if you are known to be immune.
- If you are not immune and come into contact with someone with rubella then blood tests may be advised. These can tell if you are developing rubella before symptoms begin. Further action depends on the results of these tests.
- See a doctor if you are pregnant and develop an illness that you think may be rubella. Other viruses can cause rashes similar to rubella. Most viruses do not harm the unborn child. Blood tests can confirm or rule out rubella if it is suspected.
In the unlikely case that you are confirmed to have rubella, you will be referred to an a doctor who specialises in pregnancy and childbirth (an obstetrician). The obstetrician will discuss with you the possibility of your baby having congenital rubella syndrome.
There is no effective treatment to prevent the development of congenital rubella syndrome.
How can you test for immunity to rubella?
Even if you have had a rubella (German measles) immunisation, or have had rubella infection, there is still a small chance that your body has not made enough antibodies against the rubella virus to protect you. The only way to check whether the immunisation has worked is to have a blood test. This checks for rubella antibodies. Because the congenital rubella syndrome is so important to avoid, if you are thinking about becoming pregnant for the first time, you should have a blood test to check that you are protected.
If you have not had the blood test then you should ask your practice nurse or doctor for the blood test if you are thinking about planning for a baby. If you are not immune then you can be immunised before you become pregnant.
In particular, women who have come to the UK from overseas and have not been immunised are at greatest risk of having a baby with congenital rubella syndrome. These women should also have the blood test.
Further help & information
Dr Tim Kenny
Dr Laurence Knott
Dr Helen Huins