Blood tests during pregnancy

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During pregnancy, you'll be offered blood tests to help protect your health and the health of your baby. Blood tests are an important part of your care during pregnancy.

Benefits of having blood tests in pregnancy

Having these tests could help you make decisions about your care and the care of your baby, both before and after birth.

It's your choice whether to have blood tests or not. Your decision won't affect the quality of your care.

When will I have blood tests?

Most of the tests can usually be done at one time, and the midwife will usually take blood from your arm at one of your first visits.

Some tests may be repeated routinely later in your pregnancy. This will be discussed with you.

What will my blood be tested for?

Your blood will be tested for:

full blood count, blood group and Rhesus status (positive or negative)
sickle cell and thalassaemia
infectious diseases (hepatitis B, syphilis and HIV)
Down’s syndrome
Edwards' syndrome
Patau's syndrome

Full blood count, blood group and Rhesus status

During your pregnancy you'll be offered a blood test to:

look at the red cells, white cells and platelets in your blood
find out your blood group (A, B, O or AB)
find out if you're Rhesus (RhD) positive or RhD negative

More about blood count, blood group and Rhesus status

Sickle cell and thalassaemia

Sickle cell and thalassaemia are serious, inherited blood disorders that are passed on from parents to children through altered haemoglobin genes.

People who have these conditions will need specialist care throughout their lives.

Learn more about screening for sickle cell and thalassaemia

Infectious diseases

You'll be offered a blood test for infectious diseases that can affect you and your baby, such as hepatitis B, syphilis and HIV.

These conditions are screened for because simple treatments can reduce the risks to you and your baby.

Down's syndrome

In the UK, around 1 baby in every 700 born has Down's syndrome. It's the most common chromosomal condition.

You may choose to have tests during pregnancy to find out how likely it is your baby might have Down's syndrome. This will either be a blood test or a combined blood test and scan.

Learn more about screening for Down's syndrome

Edwards’ syndrome

In the UK, around 1 baby in every 5000 births has Edwards’ syndrome. It’s the second most common chromosomal condition.

You may choose to have tests during pregnancy which can help to find out how likely it is your baby might have Edwards’ syndrome. This will either be a blood test or a combined blood test and scan.

Patau’s syndrome

In the UK, around 1 baby in every 16,000 births has Patau’s syndrome.

You may choose to have tests during pregnancy which can help to find out how likely it is your baby might have Patau’s syndrome. This will either be a blood test or a combined blood test and scan.

Learn more about screening for Patau's syndrome

Blood test results

You'll usually be able to get your test results at your next clinic visit. All results are confidential.

Occasionally technical problems can occur and you'll be asked to have another sample taken. Some tests are also routinely repeated later in pregnancy.

If further investigation is needed, you'll be contacted as soon as possible and given advice and care.

Your options following a high chance result

If you get a higher-chance screening result for Down's syndrome, Edwards' syndrome or Patau's syndrome, you can choose to have a further screening test (known as NIPT, which stands for non-invasive prenatal testing), a diagnostic test, or have no further tests.

What happens to my blood samples after testing is complete?

Any of your leftover blood samples will be stored in the laboratory for at least 12 months. This is so they can be used in the future if any test results need to be checked.

Medical research

Your personal health information will be kept private, which means it’s only shared with other staff involved in your care. Processes are reviewed regularly to make sure you’re offered the best service possible.

Your leftover blood samples may be used anonymously for other monitoring, laboratory, education and training purposes to improve the quality of patient care. This could be comparing different screening methods and developing new tests. If this happens your personal details will be removed.

Samples that are identifiable to you will never be used without your consent.

If you don't want your stored blood samples to be used for research, please ask the midwife to write ‘no research’ in the comments box on the request form.

You have rights in relation to the access and the use of your personal health information.

Learn more about privacy and confidentiality when using the NHS