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Screening for sickle cell and thalassaemia

Screening for sickle cell and thalassaemia checks if you carry genes for these conditions and could pass them on to your baby. It involves a questionnaire and blood test, ideally before you're 10 weeks pregnant.

Why screening for sickle cell and thalassaemia is done

Screening for sickle cell and thalassaemia is done to find out if there's a chance you could pass on either of these conditions to your baby.

Sickle cell disease and thalassaemia are serious conditions that affect how well your blood carries oxygen. They are caused by having 2 copies of an altered gene, with 1 passed on from each parent.

Screening can tell you if you have the condition or are a carrier of the altered gene (also called having the sickle cell trait or thalassaemia trait).

Anyone can be a carrier of sickle cell or thalassaemia, but it's more likely if your ethnic background is from:

  • Africa
  • the Caribbean
  • the Mediterranean
  • the Middle East
  • south and southeast Asia

Screening is the best way to find out if there's a chance your baby may have any of these conditions, but it's your choice if you want to have the test.

Knowing whether a baby might have these conditions can help you and your doctors make the best decisions for you and your baby.

Information:

It's important to tell your midwife or doctor as soon as possible if you or anyone related to your baby has any of the conditions being checked for.

Who screening for sickle cell and thalassaemia is for

You'll be offered screening for sickle cell and thalassaemia if you're pregnant.

It's recommended that it's done before you're 10 weeks pregnant but can be done at any time.

How to get screening for sickle cell and thalassaemia

You'll usually be given information about screening for sickle cell and thalassaemia at your first midwife appointment (booking appointment).

The screening is offered to everyone who's pregnant, but it's your choice if you want to have it.

Your midwife or doctor may book the blood test appointments for you or tell you how to book them yourself. Sometimes you may have the blood test at your booking appointment.

If you decide not to have the screening but change your mind later, speak to your midwife or GP.

Information:

Sickle cell disease is 1 of the conditions that can be checked for as part of the newborn blood spot test after your baby is born. This can be done whether or not you've had the screening in pregnancy.

How screening for sickle cell and thalassaemia is done

Screening for thalassaemia is a blood test, which is offered to everyone.

Screening for sickle cell is a questionnaire to check how likely it is your baby could get altered sickle cell genes from either parent.

If your questionnaire suggests you have a higher chance of being a carrier or you live in an area where sickle cell is more common, you'll be offered a blood test for sickle cell.

You can also ask to have the sickle cell blood test even if you are not offered it.

During the blood tests, a healthcare professional will take a small amount of blood from your arm. Your blood will be collected in a small tube and sent to a lab for testing.

There are no known risks to you or your baby from having the blood tests.

Getting the results of screening for sickle cell and thalassaemia

There are 2 possible results of the screening test for sickle cell or thalassaemia:

  • you're not a carrier of sickle cell or thalassaemia – most people will get this result and will not be offered further tests
  • you are a carrier of sickle cell or thalassaemia (or have the condition yourself) and will be offered further tests

If the test shows you're not a carrier, you will be told the results at your next antenatal appointment.

Information:

If you do not get your results at your next appointment, speak to your midwife or GP.

What happens if the test shows you're a carrier

If your blood test shows you're a carrier of sickle cell or thalassaemia (or have the condition yourself), you'll be contacted as soon as possible and offered an appointment with a healthcare professional to talk about:

  • the results and what they might mean for you and your baby
  • your choices and what happens next

The baby's father will be offered a blood test to check if they have an altered gene.

If both parents carry an altered gene, or if the baby's father cannot or does not have the blood test, you can choose to have:

Your maternity team will support you with whatever decision you make.

Find out more

Support and more information about screening for sickle cell and thalassaemia

Antenatal Results and Choices (ARC) offers support and information about screening tests and how you might feel if you're told your baby has or might have a condition.

  • Helpline: call 020 7713 7486, Monday to Friday, 10am to 5.30pm
  • Text: 07908 683004
  • Email: info@arc-uk.org

More information

Page last reviewed: 6 May 2026
Next review due: 6 May 2029