Pregnancy and baby

Screening for HIV, syphilis and hepatitis B

During your pregnancy, you will be offered a blood test for three infectious diseases. This is part of routine antenatal screening and is offered, and recommended, for all pregnant women in every pregnancy.

You will usually be offered the blood test at your booking appointment with a midwife, when you are around 8-12 weeks pregnant.

What is the blood test for infectious diseases looking for?

You'll be offered this blood test to find out if you have:

  • hepatitis B
  • HIV (human immunodeficiency virus)
  • syphilis

If you already know you have HIV or hepatitis B, you will need early specialist appointments to plan your care in pregnancy.

Why are these diseases serious in pregnancy?

Hepatitis B and HIV are passed on in blood and other body fluids through sexual contact or infected needles. Both these viruses, as well as syphilis, can be passed from mother to baby.

Hepatitis B

Hepatitis B affects the liver and can cause immediate (acute) and  long-term (chronic) illness. Pregnant women with hepatitis B need specialist care, which you will be offered if the test is positive or if you already know you have hepatitis B.

If your baby completes a course of vaccinations in the first year of its life, this greatly reduces their risk of developing hepatitis B.


HIV weakens the immune system (the body's way of defending itself against illness), making it difficult to fight off infections. If left untreated, it can lead to AIDS (acquired immune deficiency syndrome).

If untreated, HIV can be passed from a pregnant woman to her baby during pregnancy, birth or breastfeeding.

Treatment in pregnancy greatly reduces the risk of passing on HIV to the baby, from 1 in 4 (25%) to less than 1 in a 100 (1%).


Syphilis is passed on through sexual contact. It can also be passed from a pregnant woman to her unborn baby during pregnancy.

The earlier it's treated, the less chance there is of passing it on to the baby. It's usually treated with antibiotics.

If untreated, syphilis can cause serious health problems for the mother and her baby, or cause miscarriage or stillbirth.

How is the test done, and are there any risks?

A blood sample is taken from your arm. There are no risks associated with this test, either for you or your baby.

Do I need to have this test?

It's your choice whether to be tested for any or all of the infections. The tests are recommended to protect your health through early treatment and care, and to reduce any risk of passing an infection on to your baby, your partner or other family members.

If you test positive for HIV, syphilis or hepatitis B, your partner  and other family members may be offered a test for the infection. 

What if I decide not to have the blood test for any of the infectious diseases?

If you decide not to have the test in early pregnancy, you will be offered screening again by a specialist midwife before you are 20 weeks pregnant. The midwife will discuss with you the benefits of screening for these infections, for you and for your unborn baby.

You can ask to have a test for hepatitis B, HIV or syphilis at any time if you change your sexual partner or think you are at risk.

How will I get my results?

Your midwife will usually discuss your results with you before or at your next antenatal visit and record them in your notes.

A specialist midwife will contact you if you have a positive test result for hepatitis B, HIV or syphilis. This is to arrange appointments where you can discuss your results and organise a referral for specialist care services.


The screening tests will tell you if you have hepatitis B, HIV or syphilis. You will need further tests and examinations by the specialist care team to fully assess your condition, and what treatment and care you will need.

Hepatitis B

If you have hepatitis B, you will receive specialist care throughout your pregnancy and after the baby is born. Your partner and any other children you have should also be offered a test for infection and vaccination, if needed.

To prevent the baby getting hepatitis B, they will need vaccinations at the following times:

  • within 24 hours of birth (with an injection of antibodies if required)
  • at 4 weeks
  • at 8 weeks
  • at 12 weeks
  • at 16 weeks
  • at one year of age, with a blood test to check if infection has been avoided

It's very important that the baby has all six doses of the vaccine to protect their health. The doses at 8, 12 and 16 weeks will be given as part of their routine infant immunisations.


If you have HIV, you can greatly reduce the risk of passing it on to the baby through specialist care and treatment, medication, planned care for your birth and by not breastfeeding.

Your partner and any other children you have should also be offered a test to see if they need treatment.


If you have syphilis, you will need urgent referral to a specialist care team. Treatment is usually a course of antibiotics. Your care team will also offer to test your partner to see if they need treatment as well. The baby may need to be examined and given antibiotics after birth.

After your results

Be aware that you can still get all of these infections during pregnancy, even after you've had a negative test result.

You can catch sexually transmitted infections during pregnancy if you or your sexual partner take risks, such as having unprotected sex.

You can also get HIV and hepatitis B if you inject illegal drugs and share needles.

Remember, you can request testing for hepatitis B, HIV or syphilis at any time if you think you are at risk or you change sexual partner.

Screening for rubella

Screening for rubella in pregnancy is no longer offered. This is because rubella is now very rare in the UK due to the high uptake of the measles, mumps and rubella (MMR) vaccine.

The best way to protect you and your baby from rubella is to ensure you have had two MMR vaccinations. This will protect you and your baby in any future pregnancy, and give you longer-term protection against measles, mumps and rubella.

You can't have MMR vaccinations while you're pregnant, and you should avoid becoming pregnant for one month after MMR vaccination.

If you are currently pregnant and are not sure whether you've had two doses of the MMR vaccine, ask your GP practice to check your vaccination history. 

If the records show you haven't been fully vaccinated or there is no record, you should ask for the vaccination at your six-week postnatal check after your baby is born.

If you have a rash in pregnancy, tell your GP or midwife immediately.

You should let your midwife, GP or obstetrician know straight away if you have a rash or come into contact with someone who has a rash at any time during your pregnancy.

They can arrange tests, if need be, to check if you have rubella.
You should avoid any clinic or maternity setting until you have been assessed, and avoid contact with other pregnant women.

You can find more information in the Screening tests for you and your baby booklet (PDF, 4.35Mb).

Page last reviewed: 16/02/2015

Next review due: 31/10/2017


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