Asthma and pregnancy

Changes to your body during pregnancy may affect your asthma – it may become better or it may worsen, it may even reappear after not having been an issue since childhood. The key is to be aware of your symptoms and know what to do to keep your asthma under control.

On this page, you can find the following information:

Key points about asthma and pregnancy

  1. Do not stop your asthma medication unless advised by your doctor.
  2. Know the asthma warning signs to watch for.
  3. Avoid situations that trigger asthma attacks.
  4. Get the flu, whooping cough and COVID-19 vaccinations to protect yourself and your unborn child.
  5. Create an asthma management action plan with your doctor or nurse.

Could pregnancy affect my asthma?

Every woman reacts to pregnancy differently. In pregnant women with asthma, asthma control improves in about 1 in every 3 women, worsens in about 1 in every 3 women and remains the same in about 1 in every 3 women. 

Worsening of asthma symptoms can happen at any stage of pregnancy, but it seems to be most common between 17 and 36 weeks, mainly in the 6th month of pregnancy.

Asthma can also begin again during pregnancy in women who have not experienced asthma symptoms since childhood.

Warning signs to watch out for

Signs that your asthma may be getting worse include:

  • a cough that is worse at night or in the early morning, or when you exercise
  • wheezing
  • breathlessness  
  • tightness in your chest.

If you have these symptoms, speak to your doctor or asthma specialist, who will advise you on the best treatment.  

Signs of a severe asthma attack include:

  • severe difficulty with breathing, walking or talking
  • lips or skin turning blue
  • exhausted and tired due to the effort of breathing
  • wheezing stops suddenly.

If you experience any of the signs of a severe asthma attack, dial 111 and ask for an ambulance.

How does asthma affect pregnancy?

When asthma is well controlled during pregnancy, you will generally have a normal pregnancy with little or no increased risk of harm to you or your developing baby.

If your asthma is not controlled during pregnancy, it can cause possible harm to you and your baby. If you're having trouble breathing, your baby might not get enough oxygen.

Risks to your health:

  • High blood pressure during pregnancy.
  • Vaginal bleeding.
  • Pre-eclampsia, a condition that causes high blood pressure that can affect the placenta, kidneys, liver and brain.   
  • Complicated labour.

Risks to your baby's health:

  • Slow growth of your baby.
  • Low birth weight (when born, the baby appears small).
  • Preterm birth (early birth before 37th week of pregnancy).
  • Death of baby immediately before or after birth.

Image credit: Canva

Is it safe to take asthma medication during pregnancy?

Any medication you take during pregnancy can affect your baby, but most asthma treatments are safe to use when you are pregnant. Medical experts advise that it is far safer to manage your asthma with medicine than it is to leave asthma untreated during pregnancy. Keep taking your asthma medication as normal unless instructed to do otherwise by your doctor.

Preventer inhalers

  • Preventer inhalers help to control your asthma. 
  • Preventer inhalers contain a corticosteroid which does not relieve your symptoms immediately but builds up over time to reduce swelling in the airways and stop your asthma symptoms developing.
  • Use your prescribed regular preventer inhaler throughout pregnancy, even when you are well, to reduce the chance of severe asthma attacks.
  • Examples of preventer inhalers are:

Reliever inhalers

  • Relievers work quickly to reduce your symptoms straight away
  • You should use your reliever inhaler whenever you get asthma symptoms or if you are having an asthma attack.
  • Your reliever inhaler works by relaxing the muscles around the airways, allowing them to widen and making it easier for you to breathe. 
  • Everyone with asthma should have a reliever inhaler and you should always carry your reliever inhaler with you.  
  •  Examples of reliever medications are:

Steroid tablets

  • Steroid tablets contain larger amounts of medication than a preventer inhaler.
  • They are prescribed by your doctor for a short time if your asthma gets worse. 
  • Steroid tablets work to reduce the inflammation in your airways and are safe to take during pregnancy.
  • An example of steroid tablets is prednisone.

What can I do to manage my asthma and avoid an attack?

There are many things you can do to help reduce the severity and frequency (how often) of your asthma symptoms, such as:

  • Have an asthma management action plan
  • Exercise regularly.
  • Avoid smoking and exposure to secondhand smoke.
  • Avoid allergens that normally trigger your asthma. Note that if you are avoiding foods to protect your unborn child’s risk of asthma, there is no evidence that avoiding specific foods while you are pregnant/hapu prevents later development of asthma and allergy in children/tamariki.
  • Control conditions affecting the nose such as sinusitis, allergic rhinitis or hayfever.
  • Control gastro-oesophageal reflux disease (GORD) symptoms.
  • Get vaccinated for COVID-19pertussis (whooping cough) and flu.

Read more about what you can do to manage your asthma.

What about labour and delivery?

Most women do not get severe asthma symptoms during labour and delivery. Some women may be advised to have continuous monitoring of their baby during labour and delivery. If you are taking asthma medication, continue doing so during labour and delivery. During labour and delivery you have the same choice of pain medication as any woman. 

Learn more

Asthma and pregnancy NHS Choices

Reviewed by

Dr Jeremy Tuohy is an Obstetrician and Gynaecologist with a special interest in Maternal and Fetal Medicine. Jeremy has been a lecturer at the University of Otago, Clinical leader of Ultrasound and Maternal and Fetal Medicine at Capital and Coast DHB, and has practiced as a private obstetrician. He is currently completing his PhD in Obstetric Medicine at the Liggins Institute, University of Auckland.
Credits: Health Navigator editorial team. Reviewed By: Jeremy Tuohy, Researcher & Clinician, University of Auckland Last reviewed: 15 Apr 2020