Health conditions and planning a pregnancy

If you have a health condition there are steps you can take that will help you have a safer and more healthy pregnancy.

If you have a long-term health condition, there are steps you can take before getting pregnant that will help you have a safer and more healthy pregnancy. 

Skip to


Low iron (anaemia) is common among women and birthing people. It can get worse during pregnancy because you need more iron when you’re pregnant. That's why it may be a good idea to improve low iron levels if you're planning a pregnancy.

Talk to your doctor if you have symptoms of anaemia like:

  • tiredness and lack of energy 
  • breathlessness
  • heart palpitations
  • paler skin than your normal skin tone.

They can give you treatment if needed.

Having anaemia is unlikely to harm your baby, but it can lead to pregnancy complications and will make you feel unwell. If you're already pregnant, you can find out more about managing anaemia in pregnancy


Asthma does not affect your chances of getting pregnant. Most women and birthing people with the condition have a straightforward pregnancy.

However, if you are planning to get pregnant you should talk to your doctor, asthma nurse or specialist because:

  • your symptoms may get worse during pregnancy (although some people’s symptoms do not change and some improve)
  • your treatment will need to be reviewed regularly
  • poorly controlled asthma in pregnancy increases the risk of complications such as pre-eclampsia and preterm birth
  • you may need extra support to control your asthma during labour.

If your asthma is well controlled, there is little to no risk for you or your baby. Do not stop taking your asthma medication before speaking to your healthcare professional.

Asthma medications during pregnancy

Most asthma medicines are safe to use in pregnancy. Unless your asthma gets worse, your treatment will probably stay the same as before you were pregnant.

Your symptoms may get worse if you stop taking your medicine. This may harm your health and increase the risk of your baby having a low birthweight.

Managing asthma in pregnancy

There are things you can do to help manage your condition during pregnancy, such as:

  • using a preventative inhaler when you get a cough or cold – speak to a doctor about using preventer inhalers in pregnancy
  • stopping smoking 
  • avoiding things that trigger allergic reactions for you – for example, pet fur
  • avoiding hay fever triggers and controlling hay fever with antihistamines – talk to a doctor or pharmacist about which antihistamines are safe to take in pregnancy
  • exercising and eating a healthy diet
  • having the flu and COVID-19 jabs.

Make sure you tell your midwife, asthma nurse or specialist if you feel your symptoms are getting worse.

Call your GP, asthma nurse or 111 straight away if you’re:

  • using more of your reliever than usual
  • coughing or wheezing more, especially at night
  • feeling short of breath or tightness in your chest.

Any of these could mean your asthma is getting worse and needs to be checked. A health professional can review your medicines and make changes if needed.

How your asthma may affect your baby

If you have asthma there is a small risk that your baby may also have it. This is more likely if you smoke during pregnancy or if your baby is born prematurely. Find out more about the benefits of stopping smoking before getting pregnant.

Cancer and chemotherapy

Chemotherapy is a common cancer treatment where medication is used to kill cancer cells.

You should avoid getting pregnant, or getting someone pregnant during treatment, because the medicines could harm the baby. Use contraception during this time.

Some chemotherapy medicines can also affect your fertility, whatever sex you are. This means it can be more difficult to get pregnant. This is often temporary but can be permanent in some cases. Permanent infertility means you will not be able to have children without help.

If you’re about to start chemotherapy, speak to your care team about whether your fertility may be affected by the treatment. They will discuss your options with you.

Fertillity for women and birthing people

Women and birthing people who are having chemotherapy may be able to have their eggs frozen. This means the eggs can be used later to get pregnant through in vitro fertilisation (IVF).

Male fertility

Men and people assigned male at birth may be able to have a sample of their sperm frozen so it can be used for artificial insemination. Artificial insemination (also known as intrauterine insemination or IUI) is a fertility treatment that involves putting sperm straight into a woman or birthing person’s womb.

Getting pregnant after chemotherapy

Most doctors will advise you to wait 2 years after chemotherapy before getting pregnant. This is because if your cancer were to come back, it would be most likely do so within 2 years, and treatment can be more difficult if you're pregnant or looking after a young child.

Congenital heart disease

Many women and birthing people with congenital heart disease have a successful pregnancy, but being pregnant can put your heart under strain. 
The best way to help you have a healthy pregnancy is to talk to your heart specialist (cardiologist) before you start trying to get pregnant. 

Ask your GP to refer you if you haven’t seen a specialist for a long time.

Your doctor will talk to you about:

  • any medications you are taking, and if you need to change what you take
  • how your condition may affect pregnancy
  • how your pregnancy may affect your condition
  • how you will be cared for during pregnancy.

Your doctor may also examine you and do some tests. They can tell you when your condition is at a stable enough point that you might want to start trying for a baby. 

Do not stop taking your medication until you have talked to your doctor.

Your care during pregnancy

When you become pregnant you’ll be referred to a hospital maternity unit. You may be able to attend a special cardiac pregnancy clinic if there is one in your area. Ask your GP for details or contact The Somerville Foundation, which is a charity to help people with congenital heart disease.

You should be cared for by a heart specialist, obstetrician (a doctor who specialises in pregnancy and childbirth) and a midwife. The treatment you have will depend on your condition. You may be advised to give birth in hospital, where you will have more medical support. 

How your congenital heart disease may affect your baby

It is difficult to know how your condition may affect your pregnancy and baby because everyone is different. But having congenital heart disease does increase the risk of:

  • having a smaller baby
  • giving birth prematurely
  • your baby inheriting heart disease (depending on what type you have).

You may be offered extra scans during pregnancy to make sure your baby is healthy and growing well. 

These are some things you can do to protect yourself and your baby during pregnancy:

  • see your heart specialist before you start trying for a baby
  • try to understand as much as you can about your condition and pregnancy
  • follow all the specialist advice you’re given about managing your condition during pregnancy
  • go to all your antenatal appointments
  • do not stop taking your medication without speaking to your specialist first.

The British Heart Foundation has more information about heart problems and pregnancy.

Crohn’s disease

Crohn’s disease is a condition where parts of the digestive system become inflamed. Most women and birthing people who have Crohn’s disease can have a normal pregnancy and a healthy baby.

However, some treatments for Crohn’s disease can affect your ability to have a baby, whatever sex you are. Some medications can also harm your unborn baby.

Fertility problems for women and birthing people

Women and birthing people may find it harder to get pregnant during a flare-up but should find it less of an issue in between. If you have had abdominal or pelvic sepsis, surgery or adhesions, you may also find it more difficult to get pregnant.

Male fertility problems 

Crohn’s disease itself is unlikely to your fertility if you're a man or assigned male at birth. But some medications used to treat the condition may temporarily affect your ability to get someone pregnant.

Sometimes pelvic surgery is recommended as a treatment. This can lead to erectile dysfunction or ejaculation problems, which can make getting someone pregnant more difficult.   

Getting pregnant

Speak to your GP or gastroenterologist (specialist doctor) if you have any concerns about your fertility and if you want to start a family.

Whatever sex you are, your drug treatment may need to be changed while you’re trying for a baby. It’s vital that your condition is being managed well and you are in remission before trying to get pregnant. This reduces the risk of your condition flaring up during pregnancy.

Because you don’t know when you will become pregnant, the best thing to do is to keep using contraception until you have seen your doctor. Don’t stop taking your medication without getting advice first.

Eating disorders

If you have an unhealthy or disordered relationship with food, it may affect your pregnancy. Your baby may not grow as well as they should or they may be born prematurely

Eating disorders also increase the chance of miscarriage. You may also find it harder to get pregnant, particularly if you have anorexia and your periods have stopped.

If you are planning a pregnancy and think you could have an eating disorder, talk to your GP in the first instance. They can offer psychological therapies to help improve disordered eating. 

Charities like Beat can also help.

If you're already pregnant, read more about managing your pregnancy with an eating disorder


Fibroids are non-cancerous growths in or around the womb (uterus). Most people with fibroids don’t get any symptoms, but they can cause problems in some cases. This will depend on things like where your fibroids are and how big they are. 

Around 2 in every 3 women and birthing people will develop at least 1 fibroid in their life, and it’s most common if you're aged 30 to 50.

If you’re of African-Caribbean origin you are thought to develop fibroids more often than people of other ethnicities.

Fertility problems

Fertility problems may be worse if your fibroids are large or growing from beneath your womb lining into the main part of your womb (submucosal). Read more about fertility problems and fertility treatment.

Fibroid treatments and pregnancy

Most medication for fibroids should not prevent you from getting pregnant. The exception is progestogen injections, which can delay pregnancy for up to 12 months after you stop using it.

There is also a higher risk of miscarriage if you have endometrial ablation treatment. This is a minor procedure that involves removing the lining of the womb. It may still be possible to get pregnant after having this procedure, but it isn’t recommended for those who want to have children, because of the miscarriage risk.

Problems during pregnancy

If you are pregnant with fibroids it can sometimes lead to problems. There is a risk of:

If you have fibroids and want to get pregnant, speak to your GP for advice. 

Hepatitis B

Hepatitis B is a liver infection which is caused by a virus. You can get hepatitis B from blood and other body fluids, for example through sex or infected needles. It can also be passed to your baby during pregnancy or childbirth.

If you have hepatitis B it can cause flu-like symptoms, including a high temperature and tiredness, and doesn’t usually need treatment.

However, if you're pregnant with hepatitis B it can result in long-term infection and liver damage in your baby. 

See your GP if you think you might have caught hepatitis B. They will then be able to advise on what treatment you could have. Symptoms include:

  • high temperature
  • tiredness
  • pain in your upper tummy
  • feeling or being sick
  • raised skin that may be itchy (hives)
  • yellowing of the skin and whites of the eyes (jaundice).

If you're already pregnant and are worried you might have hepatitis B, you'll be tested at your booking appointment. Routine blood screening, including a test for hepatitis B, are offered  to everyone.

If you do have hepatitis B in pregnancy, you will have specialist appointments to plan your care and help protect your baby from the virus. You may need to take medication in your third trimester to help stop hepatitis B from being passed on.

Your baby can also have a vaccine after they’re born to stop them getting the virus. The right treatment plan can prevent hepatitis B in almost all cases.

They will have the vaccine as part of the 6-in-1 vaccine. They will have the first dose within 24 hours of birth, another at 4 weeks and the final dose at around 1 year old. It’s important that your baby has all doses of the vaccine at the right time.  

Thyroid problems

Thyroid problems and fertility

Having an overactive or underactive thyroid gland can make it harder for you to get pregnant. But there is no reason why you should not have a successful pregnancy and healthy baby if your condition is under control. 

Speak to your GP if you have a thyroid problem and you want to get pregnant. You may be referred to an endocrinologist (a doctor who specialises in hormone control) who can do some tests to assess your thyroid function.

It is vital that your condition is well controlled before you conceive. 

Problems during pregnancy

If an underactive thyroid is not well controlled in pregnancy, it can increase the risk of gestational diabetes.

If an overactive thyroid is not well controlled in pregnancy, it can increase the risk of:

Thyroid treatments and pregnancy

Some treatments for an overactive thyroid can harm your unborn baby, so make sure you keep using contraception until you speak to your doctor. They may suggest you switch to a different thyroid treatment while you try to get pregnant.

You're advised not to get pregnant during any radioactive iodine treatment or for at least six months afterwards as the radiation can be dangerous for your baby.

More support and information

NHS Choices has information on all conditions listed here, including common symptoms and how they are diagnosed and treated.

Asthma and Lung UK helps people with asthma and lung conditions and has information on asthma and pregnancy.

Beat is a charity that supports people with eating disorders. It offers a free support helpline.

Bumps is a website providing information on the effects that medicines, recreational drugs and chemicals can have on an unborn baby.

British Heart Foundation has more information about heart problems and pregnancy.

British Thyroid Foundation has more information about thyroid problems, fertility and pregnancy.

Cancer Research UK has more information about cancer and how it can be treated, your fertility and pregnancy.

Crohn’s and Colitis UK has more information about Crohn’s, fertility and pregnancy.

Macmillan Cancer Support provides advice on cancer and how it affects pregnancy.

The Somerville Heart Foundation supports people with congenital heart disease.

Pavord, S. et al (2020). ‘UK guidelines on the management of iron deficiency in pregnancy’. British Journal of Haematology, 188: 819-830.

NHS (2021) Asthma. Available at: (Accessed 23 March 2024) (Page last reviewed: 19 April 2021 Next review due: 19 April 2024)

NHS (2021) Asthma and pregnancy. Available at: (Accessed 23 March 2024) (Page last reviewed: 16/04/2021 Next review due: 16/04/2024)

GOV (2023) COVID-19 vaccination: a guide on pregnancy and breastfeeding. Available at: (Accessed 23 March 2024) (Page last reviewed: 23/01/2023)

NHS (2023) Chemotherapy side effects. Available at: (Accessed 23 March 2024) (Page last reviewed: 25 May 2023. Next review due: 25 May 2026)

Cancer Research UK (2020) Ways to preserve your fertility. Available at: 
(Accessed 23 March 2024) (Page last reviewed: 07/09/2020 Next review due: 07/09/2023)

NHS (2021) Living with Crohn’s disease. Available at: (Accessed 23 March 2024) (Page last reviewed: 22/04/2021 Next review due: 22/04/2024)

Crohn’s and colitis UK (2023) Reproductive health and fertility. Available at:
crohns-or-colitis/reproductive-health-and-fertility (Accessed 23 March 2024) (Page last reviewed: 04/2023 Next review due: 04/2026)

NHS (2021) Congenital heart disease. Available at: (Accessed 23 March 2024) (Page last reviewed: 07/09/2021 Next review due: 07/09/2024)

NICE (2020). Eating disorders: recognition and treatment NICE clinical guideline 69. Available at: (Accessed 23 March 2024) (Page last reviewed 16/12/2020)

NHS (2022) Fibroids. Available at: (Accessed 23 March 2024) (Page last reviewed: 09/09/2022 Next review due: 09/09/2025)

NHS (2023) Infertility. Available at: (Accessed 23 March 2024) (Page last reviewed: 9/08/2023 Next review due: 9/08/2026)

NHS (2022) Hepatitis B. Available at: (Accessed 23 March 2024) (Page last reviewed: 01/07/2022 Next review due: 01/07/2025)

NICE (2023) Hepatitis B: Scenario: Prevention of infection with Hepatitis B. Available at: (Accessed 23 March 2024) (Page last reviewed: 02/23)

Public Health England (nd) Hepatitis B factsheet. Available at: (Accessed 23 March 2024)

Y, Shuai et al (2016) ‘Low thyroid hormone in early pregnancy is associated with an increased risk of gestational diabetes mellitus’. The Journal of Clinical Endocrinology & Metabolism, Volume 101, Issue 11, Pages 4237–4243

NHS (2023) Overactive thyroid (hyperthyroidism). Available at: (Accessed 23 March 2024) (Page last reviewed: 11/04/2023. Next review due: 11/04/2026)

NHS (2021) Underactive thyroid (hypothyroidism). Available at: (Accessed 23 March 2024) (Page last reviewed: 10/05/2021. Next review due: 10/05/2024) 

Review dates
Reviewed: 23 March 2024
Next review: 23 March 2027