Infectious diseases
Updated 18 December 2024
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This publication is available at https://www.gov.uk/government/publications/screening-tests-for-you-and-your-baby/infectious-diseases
Public Health England (PHE) created this information on behalf of the NHS. In this information, the word ‘we’ refers to the NHS service that provides screening.
This short animation explains screening for infectious diseases in pregnancy.
Infectious diseases in pregnancy video
Screening for infectious diseases is recommended by the NHS.
1. Purpose of screening
To find out if you have hepatitis B, HIV (human immunodeficiency virus) or syphilis. Women who are living with HIV or hepatitis B need early specialist appointments to plan their care in pregnancy.
2. About these conditions
Hepatitis B and HIV are passed on in blood and body fluids through sexual contact or infected needles. These viruses can also be passed from mother to baby.
2.1 Hepatitis B
Hepatitis B virus affects the liver. It can cause acute (immediate) and chronic (long-term) ill health. Babies infected at birth or during the first year of life have a 9 in 10 (90%) chance of developing lifelong hepatitis B infection. This can lead to illnesses such as liver infections and cancers. The risk is reduced to around 1 in 10 (10%) if the baby completes the necessary vaccinations.
2.2 HIV
HIV weakens the immune system making it difficult to fight off infections. If untreated, it can be passed from mother to baby in pregnancy, when giving birth or by breastfeeding. Treatment in pregnancy greatly reduces the chance of passing on HIV to a baby from 1 in 4 (25%) to less than 3 in 1,000 (0.3%).
2.3 Syphilis
Syphilis is an infection passed on through sexual contact. It can be passed from mother to baby during pregnancy. If it is untreated, it can result in serious health problems for a baby or cause miscarriage or stillbirth.
3. The screening test
Blood is taken from your arm.
A blood sample being taken
A small amount of this blood is stored in the laboratory. This can be used for tests if you show signs of other infections or rashes during your pregnancy.
4. Safety of the test
There are no risks associated with the test.
5. Screening is your choice
These tests are strongly recommended to protect your health through early treatment and care. They greatly reduce any chance of passing an infection onto your baby, partner or other family members.
6. Not having the test
If you decide not to be tested, you will be reoffered screening later in pregnancy, ideally by 20 weeks.
7. Negative result
A negative result means you are ‘negative now’. This does not mean you are protected throughout your pregnancy. Protect yourself from infection and report symptoms as soon as possible to your midwife or GP. You and your partner can be tested at any time.
We recommend repeat testing if you change your sexual partner, inject drugs, are a sex worker, have a partner who is sexually active with other people or are diagnosed with a sexually transmitted infection (STI).
8. Positive result
If you have hepatitis B it is important for specialist teams to check your health before and after the birth. Your partner, any other children and close family members may need testing and vaccination.
Your baby will come into contact with your blood when they are born. Because of this, the virus could be passed onto them. It is therefore very important that your baby has all 6 recommended hepatitis B vaccinations at the correct times to protect their health. Ask your GP, practice nurse or health visitor if any of these do not happen. Vaccinations should take place:
- within 24 hours of birth
- at 4 weeks of age
- at 8, 12 and 16 weeks of age (part of routine childhood immunisation schedule)
- at one year of age
Your baby may also need an injection of antibodies (hepatitis B immunoglobin) at their first vaccination.
They will also have a blood test at their final vaccination to check if infection has been avoided.
If you have HIV you can greatly reduce the chance of passing HIV on to your baby with specialist care and treatment, drugs, planned care for your birth, and by not breastfeeding.
If you have syphilis, referral to a specialist team is needed. Treatment is usually a course of antibiotics. These are safe for your baby. The team will also offer to test your partner to see if they need treatment. Your baby will need an examination and blood tests after birth and may need antibiotics.
9. Getting my results
If your result is negative your midwife will discuss it with you. This will happen at or before your next antenatal appointment at about 16 weeks. It will also be recorded in your notes.
If you are positive for HIV, hepatitis B or syphilis a specialist midwife will contact you to arrange an appointment within 10 days. They will discuss the result, carry out further tests and plan your care with you.
Find more information and details of support groups on NHS.UK.