Topic Overview

Asthma is a fairly common health problem for pregnant women, including some women who have never had it before. During pregnancy, asthma not only affects you, but it can also cut back on the oxygen your fetus gets from you. But this does not mean that having asthma will make your pregnancy more difficult or dangerous to you or your fetus. Pregnant women who have asthma that is properly controlled generally have normal pregnancies with little or no increased risk to themselves or their developing babies.

Most asthma treatments are safe to use when you are pregnant. After years of research, experts now say that it is far safer to manage your asthma with medicine than it is to leave asthma untreated during pregnancy. Talk to your doctor about the safest treatment for you.

Risks of uncontrolled asthma to pregnant women

If you have not previously had asthma, you may not think that shortness of breath or wheezing during your pregnancy is asthma. If you know you have asthma, you may not consider it a concern if you only have mild symptoms. But asthma can affect you and your fetus, and you should act accordingly.

If your asthma is not controlled, risks to your health include:^{footnote 1, footnote 2}

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

Risks to the fetus include:^{footnote 1, footnote 2}

• Death immediately before or after birth (perinatal mortality).
• Abnormally slow growth of the fetus (intrauterine growth retardation). When born, the baby appears small.
• Birth before the 37th week of pregnancy (preterm birth).
• Low birth weight.

The more control you have over your asthma, the less risk there is.

Asthma treatment and pregnancy

Pregnant women manage asthma the same way non-pregnant women do. Like all people with asthma, pregnant women should have an asthma action plan to help them control inflammation and prevent and control asthma attacks. Part of a pregnant woman's action plan should also include recording fetal movements. You can do this by noting whether fetal kicks decrease over time. If you notice less fetal activity during an asthma attack, contact your doctor or emergency help immediately to get instructions.

Things to think about for asthma in pregnant women include the following:

• If more than one health professional is involved in the pregnancy and asthma care, they must communicate with each other about treatment. The obstetrician must be involved with asthma care.^{footnote 1}
• Monitor lung function carefully throughout your pregnancy to ensure that your growing fetus gets enough oxygen. Because asthma severity changes for about two-thirds of women during pregnancy, you should have monthly checkups with your doctor to monitor your symptoms and lung function.^{footnote 1} Your doctor will use either spirometry or a peak flow meter to measure your lung function.
• Monitor fetal movements daily after 28 weeks.
• Consider ultrasounds after 32 weeks to monitor fetal growth if your asthma is not well controlled or if you have moderate or severe asthma.^{footnote 1} Ultrasound examinations can also help your doctor check on the fetus after an asthma attack.
• Try to do more to avoid and control asthma triggers (such as tobacco smoke or dust mites), so that you can take less medicine if possible. Many women have nasal symptoms, and there may be a link between increased nasal symptoms and asthma attacks. Gastroesophageal reflux disease (GERD), which is common in pregnancy, may also cause symptoms.
• It is important that you have extra protection against the flu (influenza). Get the flu vaccine as soon as it's available, whether you are in your first, second, or third trimester at the time. The flu vaccine is effective for one season. The flu vaccine is safe in pregnancy and is recommended for all pregnant women.

Asthma and allergies

Many women also have allergies, such as allergic rhinitis, along with asthma. Treating allergies is an important part of asthma management.

• Inhaled corticosteroid medicines at recommended doses are effective and can be used by pregnant women.
• The antihistamines loratadine or cetirizine are recommended.
• If you are already taking allergy shots, you may continue getting them, but starting allergy shots during pregnancy is not recommended.
• Talk to your doctor about using decongestants you take by mouth (oral decongestants). There may be better treatment options.

Asthma medicines and pregnancy

A review of the animal and human studies on the effects of asthma medicines taken during pregnancy found few risks to the woman or her fetus. It is safer for a pregnant woman who has asthma to be treated with asthma medicines than for her to have asthma symptoms and asthma attacks.^{footnote 1} Poor control of asthma is a greater risk to the fetus than asthma medicines are.^{footnote 1} Budesonide is labelled by the U.S. Food and Drug Administration (FDA) as the safest inhaled corticosteroid to use during pregnancy. One study found that low-dose inhaled budesonide in pregnant women seemed to be safe for the mother and the fetus.^{footnote 3}

Never stop taking or reduce your medicines without talking to your doctor. You might have to wait until your pregnancy is over to make changes in your medicine.

Always talk to your doctor before using any medicine when you are pregnant or trying to become pregnant.