Screening for sickle cell and beta thalassaemia

Feelings about the results

For many people, being told they are a carrier during pregnancy is a shock, especially if they are not fully aware that they are being tested for these conditions and do not know much about them. Pregnancy is already an emotional time, and anything that makes people worry about the baby's health will be additionally stressful. (The NHS Screening Programme is working to ensure that in future everyone receives clear and consistent information and advice before and after screening.)  A booklet ‘Screening tests for you and your baby’ should now be given to all pregnant women by their midwife or GP and it gives information about screening for sickle cell and thalassaemia in early pregnancy.

A few people said they were not really too worried or shocked when they got their results. This might be because they knew the condition was in their family and they were half-expecting the result. For some people it was because they didn't fully understand the consequences until they got to talk to a counsellor. One woman who had recently arrived from Bangladesh felt she did not really understand the significance of the results until after her son was born with beta thalassaemia major.

Some people find out through a letter, and then make an appointment to see a counsellor. Others get a phone call first. Some people felt a phone call was better because they could talk straight away to the counsellor and get information and reassurance, but it can still be just as shocking as a letter. A few people used the internet to help find out more, sometimes while they were waiting to see a counsellor and sometimes when they were waiting for partner carrier screening results.

People are often concerned at first that they have some serious illness. Talking to a counsellor can help in understanding the difference between being a carrier, which does not affect your health, and having the condition. Many people commented on how helpful and supportive they found the specialist sickle cell and thalassaemia counsellors they met. 

Although most people who are carriers are generally in good health, there are some possible health effects they need to be aware of. There is a risk to sickle cell carriers of "sickling" under situations of very severe oxygen deprivation. Anaesthetics can cause problems. If you are a sickle cell carrier always notify your dentist or doctor before treatment starts to be on the safe side.“There is a small chance that you may experience pain at high altitudes (generally above 10,000 feet), including long-haul flying in unpressurised planes and mountain climbing. It is important you say you have sickle cell trait before undertaking such activities as you may need to breathe oxygen. Extreme exercise may also precipitate problems and if you are a professional athlete you should have a training programme that takes account of this.” (Sickle Cell Society Dec 2018). These problems do not apply to carriers of other unusual haemoglobins.

A few people who are beta thalassaemia carriers find they get tired and anaemic sometimes. This has no serious effect on the person's health, but it may help their doctor to know they are a carrier. Some women who are beta thalassaemia carriers become more anaemic when they get pregnant. 

Carriers of beta thalassaemia may need a special blood test (serum iron or serum ferritin test) to diagnose iron deficiency if this is a concern raised by their doctor. A normal blood test on someone who is a carrier of beta thalassaemia can look as if they have an iron deficiency when actually they don’t. If a doctor does not know that a person is a beta thalassaemia carrier they could prescribe iron medicines thinking it is iron deficiency when it is not which, in the long run, could do more harm than good. They should only take iron medicines if the serum iron or serum ferritin tests show a shortage of iron in the blood. (Local sickle cell and thalassaemia centres can provide more detailed advice on this topic.)

For these reasons, carriers are usually advised to carry a 'haemoglobinopathy' card to show to health professionals, stating that they are a carrier.

There are also some health advantages in being a carrier. Beta thalassaemia and sickle cell carriers have some protection against malaria, and there is some evidence that beta thalassaemia carriers have a lower risk of coronary heart disease.

See also sections on:

'Partner carrier screening'

'Newborn screening- the effect on parents'

'Awareness and understanding about the conditions'

'Communicating the results' 

For more information see the NHS sickle cell and thalassaemia (SCT) screening programme on GOV.UK.

Last reviewed December 2018.
Last updated
December 2018.


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