Sickle cell and thalassaemia screening in pregnancy

Sickle cell and thalassaemia are inherited blood conditions. Screening in pregnancy checks whether you carry an altered gene, so you can have the information and choices that go with it.

Who is offered it?

The NHS says everyone who is pregnant is offered screening for sickle cell and thalassaemia. Taking the test is optional. Anyone can be a carrier, whatever their background.

When is it done?

The NHS recommends doing it early: before 10 weeks if possible, though it can be done at any time. You’ll usually get information about it at your booking appointment.

How does it work?

Sickle cell: screening starts with a questionnaire about your family origin, to check how likely it is your baby could inherit altered sickle cell genes from either parent. If your answers suggest a higher chance of being a carrier, or you live in an area where sickle cell is more common, you’ll be offered a sickle cell blood test. You can ask for the blood test even if it isn’t offered.
Thalassaemia: this is a blood test offered to everyone.

A small blood sample is taken from your arm. The NHS says there are no known risks to you or your baby from the blood tests.

What do the results mean?

Not a carrier. Most people get this result and aren’t offered further tests. You’ll be told at your next antenatal appointment.
A carrier, or you have the condition. You’ll be contacted as soon as possible and offered an appointment to talk through the results and your options.

A carrier usually has no symptoms. Being a carrier is not an illness. It means you have one altered gene, and the question is whether your baby’s other parent does too.

Testing your baby’s other parent

If you’re a carrier, the NHS says your baby’s biological father will be offered a blood test to check for an altered gene. If you both carry one, or he can’t or doesn’t have the test, you can choose a diagnostic test, which is either amniocentesis or chorionic villus sampling, or choose no further tests. Early screening matters because, if both of you carry a gene, you will want time to decide about diagnostic tests. The NHS says your maternity team will support you with whatever decision you make. See chorionic villus sampling and amniocentesis.

After the birth

Sickle cell disease is also checked in the newborn blood spot test, whether or not you had screening in pregnancy. See the newborn blood spot test.

Support

Antenatal Results and Choices (ARC) offers support after a screening result: 020 7713 7486, Monday to Friday, 10am to 5.30pm (text 07908 683004).

Questions people ask

Why am I being asked about my family origin?

Sickle cell is more common in people with ancestry from Africa, the Caribbean, the Mediterranean, the Middle East, and south and southeast Asia, so the questionnaire helps work out who is offered the sickle cell blood test. Anyone can be a carrier.

Do I have to have it?

No. It’s optional.

What if I’m a carrier?

You’ll be contacted and offered an appointment to talk about the results and your options, and your baby’s other parent will be offered a test.

Is it too late if I’m past 10 weeks?

No. The NHS says it can be done at any time.