Sickle cell disorder and pregnancy : University College London Hospitals NHS Foundation Trust

This web page provides information about pre-pregnancy planning if you have a sickle cell disorder. It also explains how to manage your condition when pregnant and after delivery.

What is sickle cell disorder (SCD)?

SCD is a disorder of the body’s red blood cells that is genetically inherited and lifelong.

It is caused by an abnormality in haemoglobin, the part of red blood cells that carries oxygen round the body. Due to this abnormality, the red blood cells become inflexible, sticky and crescent (sickle) shaped. This process is known as ‘sickling’. Other blood cells and the vessels they travel in also become sticky, which:

disrupts blood flow, and
triggers an inflammatory cascade, where one inflammatory reaction causes another.

This may result in pain known as vaso-occlusive crisis or sickle cell crisis. It can also damage the organs where sickling occurs.

To find out more about SCD, please visit our web page Sickle cell disorder in adults.

SCD is the most common inherited condition in the world. It mostly affects people whose family origins are in the Middle East, Sub-Saharan Africa, parts of India and parts of the Mediterranean.

In the UK, between 12,000 and 15,000 people have SCD and nearly 300 babies are born with the condition every year. To detect SCD early, parents in the UK can have their newborns tested in the first week of life. This is done through the heel prick test, a routine part of newborn screening.

If you have SCD or are a carrier of sickle or an abnormal haemoglobin, you should find out whether your partner is also affected. You should do this before getting pregnant.

If your partner does not have SCD and is not a carrier, your baby will not have SCD. But they will be a carrier of one of your two abnormal haemoglobin genes.

If your partner has SCD or is a carrier of an abnormal haemoglobin, or if you are unsure what their haemoglobin type is, you or your haematology team can arrange an appointment at the haemoglobinopathy genetics clinic.

During this appointment, any necessary tests will be carried out. Both you and your partner may also receive specialist counselling if needed. The information and counselling will help you both decide whether to have tests during pregnancy to find out if your baby has the condition. Or you may choose pre-implantation genetic diagnosis. This involves screening the genes of embryos created through IVF for any conditions that can be passed on by the parents.

We realise that this can be a difficult decision for many couples. Further information about screening for SCD is available on the NHS website: nhs.uk/conditions/sickle-cell-disease/diagnosis

It’s important that you tell your haematology team that you are planning to have a baby. They will help you to be in the best possible health before you become pregnant. Until that time, they can advise you which contraception is best for you. To find out more, visit our web page about sexual health, contraception and preparing for pregnancy.

Your haematology team will also talk to you about any complications you may have during pregnancy. They will recommend some tests and checks, including:

a detailed scan of your heart (echocardiogram)
blood pressure, urine and blood tests
a special eye test (retinal screening) to detect problems at the back of the eyes.

If you are taking hydroxycarbamide (hydroxyurea), it’s important that you stop three months before you get pregnant. You should continue to use contraception during that time. If you experience a lot of problems due to your SCD, you may need regular transfusions to manage your condition.
Your haematology team will review any other medicines you are taking. They will also check your blood for antibodies that may have developed after blood transfusions.
Make sure that all your vaccinations are up to date.
You should start taking folic acid three months before you become pregnant.

For more information about medications, vaccinations and travel in sickle cell disorder, visit our web page.

Many women with sickle cell disorder have healthy babies and problem-free pregnancies. But pregnancy is a physically and emotionally demanding time for the mother. Complications may develop for a variety of reasons, some of which may or may not be related to the SCD.

To make sure that you and your baby thrive during the pregnancy, you will see many healthcare professionals and have frequent scans. This will help to identify any potential problems early and manage them properly.

Painful crises can be more common during pregnancy. They can be brought on by cold weather, dehydration and doing too much physical activity. If you have morning sickness (which can lead to dehydration) or any other concerns, contact your maternity unit as soon as possible.
Crises in pregnancy can also lead to worsening anaemia or acute chest syndrome. If you feel very tired, short of breath, or you think you are having a crisis, please contact your haematology team and the maternity unit as soon as possible.
Pregnant women are generally at an increased risk of developing blood clots in the legs or lungs. SCD raises this risk further. To find out more about reducing your risk of blood clots when pregnant and after birth, visit the Royal College of Obstetricians and Gynaecologists website.
You are also at an increased risk of high blood pressure during the pregnancy. This is known as pre-eclampsia and tends to happen later in pregnancy. To minimise this risk, all women with sickle cell disorder are offered low dose aspirin as soon as they get pregnant. To find out more about pre-eclampsia, visit the Royal College of Obstetricians and Gynaecologists website.
SCD may also affect the growth of your baby because it can change the way your placenta works. To find out more about having a small baby, visit the Royal College of Obstetricians and Gynaecologists website.
You are more likely than women without SCD to go into labour early or need a caesarean section. If you don’t go into labour early, your maternity team may advise you to have your labour started off (induced) at some point before your due date. This is to reduce the risk of you or your baby becoming unwell. Your obstetrician and midwife will talk to you about your options.

It’s important that you tell your haematology team and your GP as soon as you find out you are pregnant. You will have consultant-led care rather than midwifery-led care because of your SCD. But you will often see a midwife too.

You will see specialist haematology and high-risk obstetric teams throughout your pregnancy. If you didn’t have the recommended tests in the previous year, you should have them when you’re pregnant. The vaccinations below are safe in pregnancy and should also be updated if necessary:

Hepatitis B
Flu
Pneumovax®
Meningococcal B
Meningococcal ACWY.

You should have your appointments at the antenatal clinic at least every four weeks until your 24th week. And then every one to two weeks until you have had your baby. At each visit you will have your blood pressure checked and your urine tested. As well as the routine scans, you should have extra scans to check that your baby is growing normally.

Blood transfusions are not routinely given during pregnancy. If you need them, your haematology team will talk to you about this.

Your team in the high-risk obstetric clinic will assess your risk of blood clots early in your pregnancy. If there are any other risk factors that make you more likely to get a blood clot, for example if you are overweight, you may need to have daily low molecular weight heparin (LMWH) injections throughout your pregnancy. These are safe to take while you are pregnant and should be continued for six weeks after your baby is born.

Your haematology and maternity teams will tell you who to contact if you have any problems between clinic appointments. This will help to make sure that you can see your team promptly when you need them.

You should continue your folic acid (5 mg) once a day and penicillin V 250 mg twice a day.

If you have major problems with your SCD, you may need regular transfusions for all or part of pregnancy.

If you are at an increased risk of blood clots, you may need to take a blood-thinning medicine. This is usually a low molecular weight heparin (LMWH), such as enoxaparin or tinzaparin. If you don’t have to take it when you are pregnant, it is likely that we will give it to you after delivery.

You should take low-dose aspirin (75 mg a day) from early pregnancy to reduce the risk of pre-eclampsia.

Your doctor will talk to you in detail about your medicines.

If you became pregnant unexpectedly and had not stopped your hydroxyurea, you should stop it as soon as you have a positive pregnancy test.

Chelation (treatment to reduce iron overload) is also stopped in pregnancy. You may need to start it again right at the end of pregnancy if you have severe iron overload.

Like all pregnant women, you should not take ibuprofen before 12 weeks and after 28 weeks of pregnancy without talking to your doctor. This is because it could cause problems for your baby. You can take paracetamol and codeine instead as pain relief.

If you become unwell, contact the haematology advice line or the haematology team. During your first antenatal appointment, your midwife will also give you contact numbers for any pregnancy-related questions or issues.

If you have a sickle cell crisis:

We will give you strong painkillers, oxygen if needed, and fluids through a drip in your arm if you are dehydrated.
We will check other potential causes of your symptoms.
If necessary, we may prescribe you an antibiotic. We may also give you low molecular weight heparin (LMWH) injections to reduce the risk of blood clots.
We will monitor you closely, often in a high-dependency area of the hospital.
We will check your baby’s wellbeing.

You should have your baby in a hospital that is able to manage potential SCD-related complications.

You will be kept warm to reduce the risk of a crisis in labour. You may be given fluids through a drip to prevent dehydration and oxygen if needed. Blood that is suitable for you will be available in case you need a transfusion. Your baby’s heartbeat will be closely monitored.

You should be able to have a vaginal birth if there are no complications and you are in good health.

You should see an anaesthetist before you go into labour to discuss pain relief. This is often possible in the high-risk obstetric clinic.

All the usual methods of pain relief should be suitable for you, except pethidine which is not used in sickle cell disorder.

We will keep you warm and well hydrated, and may give you extra oxygen to prevent a sickle cell crisis.

We will encourage you to get up and walk about to prevent blood clots from forming in your legs. You may need to wear special stockings and have daily LMWH injections for at least a week to reduce this risk further. Depending on any other risk factors relevant to you, and after caesarean section, you may need to continue LMWH injections for six weeks.

You will be offered the support you need to breastfeed.

Parents in the UK can have their babies tested for SCD and other conditions. This involves taking a blood sample from the baby’s heel around day five after birth. This test is usually done by the community midwife when you are at home, or in hospital if you or your baby are still there.

The results usually take four weeks to come back. If there is a risk that your baby could have SCD, we can arrange for the blood test to be done in hospital. This way you can have the results on the same day or day after.

All contraceptive methods listed below are safe and effective after pregnancy:

combined oestrogen and progesterone pills
progesterone-only pills
contraceptive injections (Depo-Provera®)
hormone-releasing implants (Nexplanon®)
the Mirena® coil
barrier methods (such as condoms, sheaths and caps).

To find out more about contraception, please talk to your GP or a family planning specialist. You can also visit our web page Sexual health, contraception and preparing for pregnancy: Information for people with thalassaemia and sickle cell disorder (SCD).

SCD is the most common inherited single-gene disorder in the world.
Most women with SCD have a relatively straightforward pregnancy and a healthy baby.
If you are planning a pregnancy, let your haematology team know. They can review your medicines and vaccinations and make sure your checks are up to date.
You and your partner can meet a specialist or counsellor to talk about the risk of SCD being passed to your baby. They can also tell you about the tests available to you. This is best done in pregnancy.
A specialist team will look after you and your baby very closely during pregnancy.
We advise that you have your baby at some point before your due date.
We will offer you support to breastfeed.