Rubella and pregnancy

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 rubella immunisation, which is a part of measles, mumps and rubella (MMR) immunisation and is given to children of both sexes. See separate leaflet called MMR Immunisation.

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 - this is called congenital rubella syndrome. Problems associated with 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 20 weeks of your pregnancy, and highest of all in the first 12 weeks of pregnancy - when the baby has a high chance of catching rubella from you, in the womb (uterus). The risk is much lower if you are more than 20 weeks pregnant.

Fortunately, because most women and children are immune to rubella, congenital rubella syndrome is now extremely rare in the UK.

You should have a blood test before you become pregnant. The blood test for rubella immunity 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 MMR vaccine, which falls within the routine childhood immunisation programme. Two doses are needed for full immunity and over 9 out of every 10 children under 2 years of age in the UK have had at least one dose. However, in an extremely small number of children, immunisation does not work well or does not last into adulthood. This means that some adults who have been immunised are not actually immune to rubella.

• The only way to check whether you are immune is to have a 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.

• Prior to April 2016 a blood test for rubella immunity was offered to all pregnant women in the UK, so if you were pregnant prior to this time there should be a record of your test. Rubella immunity tests are also normally offered if you have any blood tests for infertility, or if you have had fertility treatment.

• Women who have come to the UK from overseas may not have been immunised against rubella, as countries' immunisation programmes differ. If they have not been immunised or become immune to rubella by having the disease then are then at risk of acquiring rubella in pregnancy and of having a baby with congenital rubella syndrome.

• Rubella is still widespread in many parts of the world, such as Africa and Asia. If you're planning to travel outside of the UK and are pregnant or thinking of becoming pregnant, it's worth checking your rubella status with your GP.

• If your rubella blood test shows that you are not immune, and you are not already pregnant, then you should be immunised. This means having the MMR vaccine. See separate leaflet called MMR Immunisation.

It used to be routine practice to screen for rubella (German measles) antibodies in pregnancy. Since April 2016 this test has not been offered. This is because rubella infection rates are now very low in the UK and infection in pregnancy is very rare. It is also thought better to check immunity from rubella before you are pregnant, as the test can become unreliable when you are pregnant and it is much better to do it before.

Rubella (German measles) is normally acquired through close contact, such as being in the same room with, and close to, an infected person. If you are pregnant and come into contact with someone with (or suspected of having) rubella, you should take steps to check your rubella status. Your midwife or doctor may have a record of this (from previous blood tests). Most women are immune due to previous immunisation and will not develop rubella.

• If you are known to be immune (which means you have TWO previous blood results showing immunity, or ONE immune blood result plus a documented vaccination, or TWO documented doses of vaccine) then no further action is needed to prevent rubella. However, you may need to be tested for slapped cheek disease (parvovirus B19):

  • Slapped cheek disease is a viral illness which can look rather like rubella. If you are pregnant and come into contact with an illness that might be rubella then unless it is confirmed by blood tests, it might also be due to parvovirus B19. Most adult women are immune to parvovirus B19 but a few are not. If you develop slapped cheek disease prior to 14 weeks of pregnancy there is risk of your baby developing anaemia in the womb (uterus), and of having a miscarriage. Therefore, if you contact a person with an infection that might be rubella prior to 14 weeks of pregnancy then, even if you are immune to rubella, your doctor may suggest a blood test to rule out parvovirus B19 infection.

• If you are not immune to rubella, or you don't know about your immunity, and you come into contact with someone with rubella (or suspected rubella) when you are pregnant then blood tests are usually advised. These can tell if you are developing rubella before symptoms begin. Further action depends on the results of these tests. The tests are done however pregnant you are, even though congenital rubella syndrome does not develop if you have rubella after 20 weeks of pregnancy.

• 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.

In the unlikely case that you are confirmed to have rubella, you will be referred to 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.

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.

Dr Mary Lowth is an author or the original author of this leaflet.