Asthma and pregnancy

It's hard to predict how being pregnant may affect your asthma - it's different for every woman.

Some pregnant women find their asthma improves, while some don't notice any changes in their symptoms at all. Nasal congestion and hay fever can get worse for some women when they're pregnant. Unfortunately some women - mostly those who already have severe asthma - find their asthma symptoms get worse when they're pregnant.

If you notice that your asthma and/or hay fever symptoms are getting worse, your GP, asthma nurse, pharmacist or consultant are there to support you. They can tell you what medicines are safe to take during your pregnancy and talk you through all the things you can do to stay well with your asthma. Make an appointment as soon as possible.

Most asthma medicines are safe to use in pregnancy, and continuing to take your medicines exactly as prescribed is the best way for you to stay well with your asthma. What's reassuring is that the risk of complications because of your asthma is very small to both you and your baby.

On this page:

When you first find out you're pregnant

When you find out you're pregnant, make an appointment to see your GP or asthma nurse as soon as you can. This is a chance to review your asthma medicines and check that your written asthma action plan is up to date. Tell your midwife you have asthma and make a note of it in your birth plan.

Staying well when you're pregnant

It's important for you and your baby that your asthma is well managed during your pregnancy. You can lower your risk of asthma symptoms, and of having an asthma attack, by:

  • taking your asthma medicines as prescribed and discussed with your GP or asthma nurse, even if you're not having any symptoms
  • reviewing your asthma action plan with your GP or asthma nurse and making sure you're using your inhaler(s) in the most effective way - ask your GP, asthma nurse or pharmacist to check your inhaler technique.

If you have difficult or severe asthma, ask your GP or asthma nurse if you need an asthma specialist as well as an obstetrician caring for you during your pregnancy.

Don't smoke!

Women who smoke while they're pregnant are more likely to have babies with breathing problems, including asthma. Smoking while pregnant also increases your risk of miscarriage and premature labour - if your baby is born too early their lungs won't be fully developed and they'll be more at risk of wheeze in childhood.

Smoking isn't good for your asthma, for your baby or for your health generally. You can find support to stop smoking at, call the NHS Smoking Helpline on 0300 123 1044, or ask your GP or pharmacist about local support programmes. Don't forget to ask friends and family to avoid smoking around you, as second-hand smoke also increases your risk of asthma symptoms and an asthma attack.

Eat well

The best advice for all pregnant women is to eat a healthy, balanced diet with plenty of fresh fruit and vegetables. This will give your baby all the nutrition it needs to grow.

In the past, the UK Government advised pregnant women to avoid eating peanuts, but following a major review of the scientific evidence in 2009, this guidance has been changed and the advice now is that it's safe to eat peanuts while you're pregnant, unless you're allergic to them.

Common concerns

Will my asthma medicine harm my baby?

The medicines used to treat asthma are safe in pregnancy and won't harm your baby. This includes reliever inhalers (usually blue); preventer inhalers; long-acting and combined relievers; theophylline; and steroid (prednisolone) tablets. There are more risks to both you and your baby if you don't take your medicines and your asthma gets worse.

The group of medicines called leukotriene receptor antagonists (called Montelukast and Zafirlukast) would not normally be started during pregnancy, but if you were taking one of these before you got pregnant and it was working well for your asthma, your GP or asthma nurse will weigh up what's best for you and your baby and may advise you to continue taking it to help you stay well with your asthma.

Don't hesitate to talk to your GP, asthma nurse or pharmacist if you have any questions or concerns about your medicines when you're pregnant. You can also talk about medicines and any potential side effects during your asthma review.

Is it safe to have the flu vaccine?

Yes. The flu vaccine is recommended for pregnant women as well as for some people with asthma, because of the higher risk of developing complications from flu. It's safe to have the flu vaccine at any stage of your pregnancy. Having the flu vaccine while you're pregnant will also protect your baby from flu in the first few months of its life.

What should I do if my asthma gets worse while I'm pregnant?

If you notice that your asthma symptoms are getting worse, make an appointment to see your GP or asthma nurse as soon as possible so they can review your medicines and make any changes if necessary.

Sometimes a short course of steroid tablets may be prescribed. These are safe to use during pregnancy. To reduce your risk of your asthma symptoms getting worse, continue to take your preventer inhaler regularly and use your reliever inhaler when you need it to relieve symptoms.

If you find that you're using your reliever inhaler more than three times a week, speak to your GP or asthma nurse as this may be a sign that your asthma isn't well managed.

What should I do if I have an asthma attack while I'm pregnant?

Having an asthma attack is always an emergency whether you're pregnant or not. Make sure you, and the people around you, know what to do in an asthma attack.

Will my baby develop asthma?

We don't know the exact cause of asthma, but we do know that asthma often runs in families. Your baby is more at risk of developing asthma or breathing problems if:

  • you smoke while you're pregnant or you smoke around your child when they're born
  • both parents have asthma. If only one parent has asthma, the baby has a greater chance of developing asthma if it's the mother who has asthma rather than the father
  • your baby is born prematurely.

Remember, if you have any questions about managing your asthma during pregnancy, you can always call the Asthma UK Helpline on 0300 222 5800 (Mon – Fri; 9am – 5pm) to speak to one of our friendly asthma nurses. They'll be happy to help and put your mind at ease.

Helpline quote on pregnancy

Giving birth

What if I have an asthma attack during labour?

Asthma attacks during labour are very rare because your body produces hormones (cortisone and adrenaline) that help with labour. These natural steroid hormones also help prevent asthma attacks. Even if your asthma became worse during your pregnancy, these symptoms usually reduce during the later stages of pregnancy.

If you do have asthma symptoms during labour, it's safe to use your reliever inhaler (usually blue) as normal. It won't harm your baby in any way. If you're on high doses of steroids, and have been for more than two weeks before you go into labour, make sure you tell your midwife and/or the hospital staff as they'll need to make sure you continue to take these medicines while you're in labour.

Some people with asthma also have a latex allergy. If you do, make sure you tell your midwife and the hospital staff so they can use latex-free gloves.

Talk to your GP, asthma nurse or midwife during the weeks and months before your due date and make sure your asthma is included in your birth plan. This can help reduce any fears you may be having about asthma and giving birth.

What about pain relief during labour?

There are a number of different ways to relieve pain during labour. Pain relief injections (usually Pethidine) and epidurals (a special type of local anaesthetic which numbs the nerves that carry the pain impulses from the birth canal to the brain) are safe for women with asthma. Gas and air (Entonox) is safe for most women with asthma. If you have severe asthma, your GP, midwife and/or obstetrician will discuss whether or not it's suitable for you when you create your birth plan.

If you need to have a caesarean (also known as a C-Section), you may be advised to have a local anaesthetic rather than a general one, if possible.

After the birth


There are so many benefits to breastfeeding that the Department of Health advises women to breastfeed exclusively (only feeding your baby with breast milk) for the first six months if possible. After that, you can continue breastfeeding alongside feeding your baby other foods for as long as you and your baby want to.

It's safe to breastfeed your baby when you're taking asthma medicines:

  • Only very small amounts of asthma medicines pass into breast milk and these are no risk to your baby.
  • Medicines prescribed for asthma don't affect your body's ability to make breast milk.
  • If you're able to, breastfeeding is the best choice for your baby. Some research suggests that breastfeeding may help reduce the chance of babies developing asthma.

If you decide to bottle-feed your baby for whatever reason - maybe it's not possible, you're not enjoying it or you need to go back to work - it doesn't mean your baby will develop asthma. Speak to your midwife or health visitor about the best milk formula to use.

You can also call the Asthma UK Helpline on 0300 222 800 (9am – 5pm; Mon – Fri) to talk to one of our specialist asthma nurses about how to stay well with your asthma during pregnancy.

Last updated June 2016

Next review due June 2019