How to manage your asthma during pregnancy

When you’re pregnant, it’s natural to worry about, well—everything. Is your baby developing normally? Are you getting enough nutrients to support two or more humans? Is worrying too much bad for your baby? And if you’re one of the 4% to 8% of pregnant women with asthma, you have to add breathing difficulties—and the medications used to treat them—to your list. 

Asthma is a chronic condition that causes airways in the lungs to narrow, swell, spasm, and produce extra mucus. This leads to chest tightness, coughing, wheezing, and other breathing problems, like shortness of breath. Should you expect worsening symptoms of asthma in pregnancy—or complications?

Asthma and pregnancy: What to expect when you’re expecting

Pregnant women with well-controlled asthma generally do fine during pregnancy, experts say. 

“Having asthma doesn’t mean you’re doomed to have pregnancy complications,” notes Hector O. Chapa, MD, FACOG, clinical assistant professor of obstetrics & gynecology at Texas A&M College of Medicine. “This is a very treatable and manageable condition that shouldn’t take away from the joy of pregnancy. Many women with asthma have healthy pregnancies.”

During pregnancy, you could see your asthma symptoms change due to the changes in your body. You may be at higher risk of asthma symptoms, so it’s important to speak with your provider about keeping up with your long-term medicines such as inhaled corticosteroids.

Will asthma affect my pregnancy?

Uncontrolled asthma, on the other hand, can cause some serious pregnancy complications. Your asthma is considered “uncontrolled” if you need to use a rescue inhaler (to open up airways) two or more times a week; wake at night with breathing difficulties two or more times a month; or need to refill your prescription for said rescue medication two or more times a year. Some of those complications include:

• Preeclampsia: This is a condition characterized by very high blood pressure, fluid retention, vision changes, and a severe headache. Researchers aren’t exactly sure why asthma and preeclampsia seem to be related, but they suspect it may be due to the inflammation asthma causes. This inflammation can restrict blood flow to the placenta and the baby it’s nourishing, driving blood pressure up. One study comparing pregnant women with severe asthma to those whose asthma was controlled found that the women with severe asthma were 30% more likely to develop preeclampsia than their controlled counterparts.
• Small for gestational age (SGA): An SGA newborn has a weight that is less than 10th percentile for age and gender. In one study, pregnant women with severe or moderate asthma were 48% and 30% more likely to give birth to an SGA baby than women with mild asthma. Asthma can impact oxygen levels, which, in turn, can impact blood supply to a developing baby, affecting its growth.
• Lower birth weight: A study published in the Journal of Allergy and Clinical Immunology found that women with asthma gave birth to infants who weighed 38 grams (about 1.3 ounces) less than babies delivered by women without asthma. Women with uncontrolled asthma had babies nearly 2 ounces lighter. Again oxygen—or the lack of it—seems to be a factor. “Poor oxygenation of mom can lead to poor oxygenation of the placenta and growing baby,” explains Heather Figueroa, MD, an OB-GYN at Loma Linda University Health.

How to treat asthma during pregnancy

The best way to avoid any negative outcomes of asthma and pregnancy is to make sure to prevent symptoms with lifestyle changes and medications.

Pregnancy-safe asthma medications

Pregnant or not, don’t stop taking any of your asthma medications without first talking to your healthcare provider. “In general, most asthma medications are safe to use in pregnancy,” Dr. Chapa says. “OB-GYN physicians agree that the risks of uncontrolled asthma are much greater than any theoretical risks of asthma medications. As always, medications that act more locally are preferred. This means that inhalers are the first line of treatment because they’re less likely to pass to the fetus.” In fact, it is better to use a daily controller medication (usually an inhaled steroid) than to have an asthma exacerbation, which may harm the baby and also expose both of you to more systemic medications.

According to the American Academy of Allergy, Asthma, and Immunology (AAAAI) and other experts, some of the safe-to-use asthma medications include:

• Inhaled corticosteroids, such as Pulmicort Flex (budesonide): When used regularly over time, these medications can reduce inflammation in the airways and help keep serious asthma attacks at bay. “The use of a maintenance inhaler can reduce asthma exacerbations—events that can put both mother and baby at risk of hypoxemia [low oxygen in the blood]—and increase exposure to more medications that might not have otherwise been necessary,” Dr. Figueroa notes. 
• Anti-leukotriene agents, like Singulair (montelukast) and Accolate (zafirlukast) are relatively safe during pregnancy; however, Zyflo (zileuton) is not. These medications work preventively to keep the airways open and reduce mucus in airways.
• Long-acting beta agonists may be used in combination with inhaled corticosteroids as daily management medications.
• Short-acting Beta 2 agonists, such as albuterol: These are quick-acting drugs (also known as rescue medications), sometimes taken through an inhaler or nebulizer (a machine that turns liquid medicine into a mist), to provide immediate relief to breathing problems. 
• Atrovent (ipratropium): “This is a specific type of medication called an anticholinergic,” explains Dr. Chapa. “It’s usually used as an inhaler and works similar to albuterol to relax airways.”
• Cromolyn sodium inhaled (via a nebulizer): This prevents the release of substances in the body that can cause airway inflammation. This is a prevention medication.

“In cases of severe asthma attacks that are not alleviated by these options, physicians may

prescribe oral steroids [such as prednisone] for five to seven days to reduce airway inflammation,” adds Dr. Chapa.

Lifestyle changes

Medication isn’t your only tool to help with troublesome asthma flares during pregnancy. To help ensure a healthier pregnancy:

• Avoid any known asthma triggers. If dust, animal dander, cleaning products, chemicals, or cigarette smoke make your asthma worse, steer clear of them when you can. 
• Quit smoking or vaping, including non-tobacco substances such as marijuana. It will improve asthma symptoms, and reduce risk of pregnancy complications due to asthma, nicotine exposure, or smoke.
• Get a flu shot if you’ll be in your second or third trimester of pregnancy during flu season.
• Get a COVID-19 vaccine.
• Stay in communication with your healthcare provider. That means keeping appointments, getting recommended tests, and taking your asthma medications as directed.
• Stay healthy with regular exercise and good nutrition. Unhealthy weight gain exacerbates asthma. Good cardiovascular fitness promotes good lung health.

Common asthma and pregnancy FAQs

Asthma can be a serious health problem—of course you have questions about how it might affect your pregnancy. Here, some common questions and their answers:

Can pregnancy cause asthma?

No, you won’t develop pregnancy-induced asthma. But pregnancy can worsen what may have been mild (and easily overlooked) asthma symptoms you had pre-pregnancy. What’s more, pregnancy itself can lead to some breathing problems that might be mistaken for asthma. “A growing uterus can make a woman feel short of breath because it becomes harder to breathe deeply,” Dr. Figueroa says. “Sinus passageways can also become a little more swollen in pregnancy, and thus can be more sensitive to allergies and feelings of congestion. And activity can make a woman feel more easily ‘winded’ or short of breath.” While these things can make breathing harder, they usually don’t cause wheezing, coughing, or chest tightness—the hallmarks of asthma.

Can pregnant asthma patients have a normal delivery?

Yes. It’s not very likely that you’ll have an asthma attack during labor or delivery. For reasons that aren’t entirely clear, the vast majority of women see an improvement in their asthma during labor and delivery. Only about 10% will have an exacerbation, which can be effectively treated, especially in a hospital setting.

Can I pass asthma on to my baby?

You might. One of the factors that influence development of asthma is genetics. Also, women who experience pre-eclampsia are more likely to have a child with asthma.

Are there any asthma medications that aren’t safe to use during pregnancy?

There are a few. “Theophylline [a drug that relaxes airways] is a particular medication that’s considered controversial and contraindicated in pregnancy,” says Dr. Chapa. “Some animal studies that used this medication, at much higher doses than in humans, found a possible link between its use and certain birth defects. However, this has not been well-studied in pregnancy. For this reason, this medication is not advised.” Good adherence to asthma prevention medication regimens will reduce the need for more harmful medications.

As an asthmatic, will I need extra monitoring during pregnancy?

That depends. If you have moderate-to-severe asthma, you may need to work more closely with your primary care provider or consult a pulmonologist as well as your obstetrician.