Pregnancy and Asthma

Managing your asthma while pregnant is the best thing you can do for you and your baby.

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When you’re pregnant, it is particularly important to manage your asthma properly.

According to the Centers for Disease Control and Prevention, asthma affects 4–12 percent of women in their childbearing years. Bronchial asthma is considered the most common chronic disease in pregnancy, complicating 4% to 8% of pregnancies. Most methods for controlling asthma are not harmful to your developing baby, and your baby will develop better if you are breathing easily.

Tell all your doctors that you have asthma. And if you’re pregnant or planning a pregnancy, talk with your allergist. Allergists are specially trained to help you take control of your asthma, so you can live the life you want – including becoming pregnant. A close partnership with your allergist is the secret to well-managed asthma.

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Effects of Pregnancy on Asthma

There is no significant risk to you or your unborn child if your asthma is well controlled, but uncontrolled asthma can cause serious complications. For you, the mother, these complications include high blood pressure, toxemia, premature delivery and, rarely, death. For your baby, complications include increased risk of stillbirth.

While pregnant, about a third of women with asthma experience improved symptoms, about a third have worse symptoms and about a third experience no change.

Studies on the overall effect of pregnancy on asthma have found the following:

  • While pregnant, women with severe asthma are more likely to see their asthma worsen, whereas women with mild asthma are more likely to see improvement or no change.
  • The change a woman experiences during her first pregnancy is usually similar in future pregnancies.
  • Asthma is most likely to worsen during weeks 24 to 36. About 10 percent of women with asthma have symptoms during labor and delivery.
  • If asthma symptoms change during pregnancy, they usually return to pre-pregnancy status within three months of delivery.

Pregnancy may affect women with asthma in several ways. Hormonal changes that occur during pregnancy can affect both your nose and sinuses, as well as your lungs. The increase in estrogen contributes to congestion, which causes a stuffy nose, especially during the third trimester. A rise in progesterone may cause a feeling of shortness of breath. Your allergist can help determine if asthma is the cause of your shortness of breath during pregnancy.

Treatment and Management

Don’t be afraid to take your asthma medication during pregnancy. Your allergist will help you choose medications that can be taken safely while pregnant.

Asthma symptoms can vary in intensity from day to day, month to month or season to season, regardless of pregnancy. You and your allergist should create a treatment plan based on the severity of your asthma and your experience with asthma medicines while pregnant. Remember that medicines should not replace avoidance of your triggers. Avoiding irritants and triggers may reduce the amount of medicine you need.

Your allergist will take the following into consideration when discussing the use of asthma medicines during pregnancy:

  • Inhaled medicines are generally preferred because they have a more targeted effect, with only small amounts entering the bloodstream.
  • When appropriate, time-tested medicines are preferred, because there is more experience with their use during pregnancy.
  • It is best to limit medicines as much as possible in the first trimester, when the baby is first developing. But birth defects from medications are rare; no more than one percent of all birth defects are caused by medicines.
  • In general, the same medicines used during pregnancy are appropriate during labor and delivery and when nursing.

Fortunately, most asthma patients do well during labor and delivery, although the baby should be monitored closely. In low-risk women whose asthma is well controlled, the routine monitoring that is conducted with all babies should be sufficient. More intensive monitoring with careful observation is recommended for women who enter labor and delivery with severe asthma or other risk factors.

The most important goal is to maintain control of your asthma throughout your pregnancy. The best way to meet this goal is to follow your treatment plan and to take your medications as directed.


There is no research that indicates you can develop asthma from being pregnant. However, pregnancy can cause asthma symptoms to worsen. It’s possible that a woman who does not realize she has mild asthma will recognize asthma symptoms for the first time while pregnant. However, most women with asthma are aware of their asthma prior to becoming pregnant.

If uncontrolled, severe asthma may be harmful to your developing baby. However, if well controlled, it should not have any effect on you or your baby.

Your asthma may worsen, stay unchanged or possibly improve during pregnancy. Although it cannot be accurately predicted in a first pregnancy, asthma usually follows a similar pattern in the pregnancies that come after. For reasons not totally understood, asthma usually improves during labor and delivery, but even if a severe attack occurs, appropriate treatment can be given, and complications are rare.

Most medicines used to treat asthma appear to be safe during pregnancy, especially those that have been around for many years and have been studied. Though no medicine has been proven entirely safe for use during pregnancy, your allergist will carefully balance medication risks and the need for symptom control. Your treatment plan will be individualized, so that potential benefits outweigh the potential risks of your medications or of uncontrolled asthma.

No. A moderate to severe asthma attack could be a risk to both you and the baby. The risks of stopping your medication are far greater than any potential risk to your baby from medication. Therefore, do not stop your regular asthma medication without first discussing it with your primary care physician or your allergist.

Unless a life-threatening illness requires their use, the following medications should be avoided during pregnancy, either entirely or during certain stages:

  • Sulfonamides (the sulfa drugs) are safe early in pregnancy, but their use in the last trimester might cause jaundice in your infant.
  • Tetracyclines at any stage of pregnancy may cause skeletal and dental deformities.

Many of them are safe. Consult your allergist before continuing antihistamines or nasal sprays, even if they are available over the counter.Accordion Content

The developing baby depends on you to supply oxygen for growth and survival. Uncontrolled asthma causes a decrease in your oxygen, which in turn reduces the oxygen flow to your baby. This may result in impaired growth or other complications.

This page reviewed for accuracy June 28, 2023.