Guidance

Information and choices for women and couples at risk of having a baby with sickle cell disease

Updated 12 January 2021

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This publication is available at https://www.gov.uk/government/publications/baby-at-risk-of-having-sickle-cell-disease-description-in-brief/information-and-choices-for-women-and-couples-at-risk-of-having-a-child-with-sickle-cell-disease

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.

Who this information is for

You should read this information if the result of your antenatal screening test for sickle cell and thalassaemia (SCT) shows you are at risk of having a baby with sickle cell disease.

This is because your blood test showed that:

  • you and your baby’s biological father are both carriers, or
  • you are a carrier and we do not have test results for your child’s biological father

This information will help you and your health professional talk through the next stages of your care during this pregnancy. It should support, but not replace, any discussions you have.

This information explains:

  • what sickle cell disease is
  • the chances of your baby being born with sickle cell disease
  • possible follow-up tests
  • choices available to you

Sickle cell disease

Sickle cell disease is the name for a group of conditions inherited from biological parents that affect the haemoglobin in red blood cells. The most serious type is called sickle cell anaemia.

In the UK, sickle cell disease is most common in people with an African or Caribbean family background, but it is also seen in people with family origins from other parts of the world.

People with sickle cell disease have red blood cells that can become misshapen, which:

  • can cause problems by blocking small blood vessels
  • do not last as long as healthy red blood cells

Sickle cell disease is a serious lifelong condition, but long-term treatment can help manage many of the symptoms. People with sickle cell disease can lead long, active and fulfilling lives if they manage their condition well and have the right care and support.

Symptoms

The main symptoms of sickle cell disease are:

  • painful episodes called sickle cell crises, which can be very severe and last up to a week
  • an increased risk of serious infections
  • anaemia (a reduction in red blood cells that means not enough oxygen is carried around the body), which can cause tiredness and shortness of breath

Other symptoms can include delayed growth, strokes and lung problems.

Treatment and longer-term health

People with sickle cell disease need specialist care throughout their lives. Daily antibiotics and regular vaccinations can reduce the risk of infections. Blood transfusions can also be given to treat serious cases of anaemia. Some children with sickle cell disease benefit from taking a medicine called hydroxycarbamide which helps prevent many complications.

People with sickle cell disease can do a number of things to manage pain, avoid infections and stay as healthy as possible. Your healthcare professional can give you more advice about living with sickle cell disease.

The only cure for sickle cell disease is a bone marrow (or stem cell) transplant, which replaces damaged blood cells with healthy ones. This is a complicated procedure which is only suitable for people with serious complications from the disease who have a matching donor.

Causes

Sickle cell disease is inherited from genes passed on by both biological parents. It is not a result of anything you have or have not done.

If both biological parents are carriers of the haemoglobin gene, known as haemoglobin S, their baby can inherit the haemoglobin S gene from both of them. This is the most common and most serious type of sickle cell disease.

Babies can inherit other types of sickle cell disease if one parent carries the sickle cell gene (haemoglobin S) and the other parent has another haemoglobin gene such as beta thalassaemia or haemoglobin C. Your health professional can discuss this with you, so that you understand exactly what condition your baby could inherit, and how serious it could be.

The chances of your child inheriting sickle cell disease

If you and your child’s biological father are both carriers then there is a 1 in 4 (25%) chance your child will inherit sickle cell disease. There is a 2 in 4 (50%) chance that your child will be a carrier, and a 1 in 4 (25%) chance your child will have normal haemoglobin. These chances are the same in every pregnancy when both parents are carriers.

The diagram below shows how genetic inheritance works. Both parents in this diagram are carriers. They are drawn in 2 colours to show they have one usual haemoglobin gene (green) and one unusual gene (blue).

Inheritance diagram when both parents are carriers of an unusual haemoglobin gene, showing there is a 1 in 4 chance of the baby inheriting a condition, a 2 in 4 chance of them being a carrier and a 1 in 4 chance they will have normal haemoglobin.

There is a 1 in 4 chance of this baby inheriting the condition, a 2 in 4 chance of them being a carrier and a 1 in 4 chance they will not have the condition.

Follow-up tests

You can choose if you want a test to find out for sure if your unborn baby has inherited sickle cell disease or not. This is called prenatal diagnosis (PND). It is your decision to have this test or not.

All babies are offered the newborn blood spot test for sickle cell disease whether a PND has been carried out or not. The test is offered when the baby is 5 days old and results received before the baby is 28 days old.

If you decide to have PND

You will be offered either a chorionic villus sampling (CVS) or amniocentesis diagnostic test.

CVS tests are usually done between 11 and 14 weeks of pregnancy but can be done later.

Amniocentesis tests are usually done between 15 and 20 weeks of pregnancy.

PND test results

There are 3 possible results from a PND test. It can show that your baby:

  • has inherited sickle cell disease (1 in 4 or 25% chance)
  • is a carrier (2 in 4 or 50% chance)
  • has usual haemoglobin A (1 in 4 or 25% chance)

In rare cases the screening laboratory cannot give a result. If this happens, you will be contacted and offered a repeat PND test.

Next steps and choices

If the result shows that your baby has normal haemoglobin or is a carrier, then your pregnancy care will continue as usual.

If a PND test shows your baby has inherited sickle cell disease, your healthcare professional will talk to you and offer support. You should also have the chance to talk to a specialist.

You may choose to:

  • continue with your pregnancy
  • end your pregnancy (have a termination)

If you decide to continue with the pregnancy the specialist team will:

  • help plan your care and the birth of your baby
  • provide information and advice about caring for a child with sickle cell disease
  • offer you the newborn blood spot screening test after your baby is born, and you should receive the result before your baby is 28 days old

If you decide to end your pregnancy the specialist team will give you information about what this involves and how you will be supported.

Only you know what is the best decision for your family.

Whatever decision you make, your healthcare professionals will support you.

Planning for pregnancy

If you and your partner are planning a pregnancy and are both carriers, there is a 1 in 4 (25%) chance your baby could inherit sickle cell disease. These chances are the same in each and every pregnancy that you have together.

You may discuss the following with your GP, midwife or specialist counsellor:

Prenatal diagnosis (PND) early in a future pregnancy

This can be performed after 11 weeks giving more time to consider your choices if the baby has sickle cell disease. You would need to see your GP or midwife as soon as you know you are pregnant.

Pre-implantation genetic diagnosis (PGD)

PGD is a reproductive treatment used in in-vitro fertilisation (IVF) which involves checking the genes or chromosomes of your embryos for a specific genetic condition. It can help to avoid a pregnancy with a genetic condition for which a couple is at risk. You can ask to see a genetic counsellor to discuss this option.

Assisted pregnancy using donated eggs or sperm from people who are not carriers

This means either you or your partner would not be a biological parent of your baby. You can discuss this option with your healthcare professional.

More information

For more information, see:

The NHS Screening Programmes use personal information from your NHS records to invite you for screening at the right time. Public Health England also uses your information to ensure you receive high quality care and to improve the screening programmes. Find out more about how your information is used and protected, and your options.

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