What is Asthma in Pregnancy?

Bronchial asthma, or simply asthma, is a long-term condition that commonly becomes more severe during pregnancy, affecting between 4% to 8% of pregnant women. Asthma is mainly characterized by inflammation in the airways, causing increased sensitivity to various triggers. Typically, asthma is not constant, but comes and goes in episodes. Critically, asthma attacks, while often short, pose a significant risk during pregnancy and can lead to health issues for both the mother and the baby. Past research has shown that nearly 6% of pregnant women have been hospitalized due to severe asthma episodes.

What Causes Asthma in Pregnancy?

We don’t fully understand the reasons, predictors, and outcomes of asthma attacks during pregnancy. Past research has suggested that the more severe the asthma, the higher the likelihood of an asthma attack during pregnancy. Some studies have highlighted a main risk factor: pregnant women not taking their regular asthma control medication, often because they’re worried it could harm their unborn baby. Catching a respiratory virus could also increase the risk of having an asthma attack during pregnancy.

Risk Factors and Frequency for Asthma in Pregnancy

In the United States, about 8.4% to 8.8% of pregnant women have bronchial asthma. However, this number can vary in other countries. We need more information to understand this trend worldwide. Keep in mind that the way bronchial asthma is diagnosed can differ based on population characteristics.

Signs and Symptoms of Asthma in Pregnancy

About one-third of pregnant women experience worsening asthma symptoms during pregnancy, while symptoms in another third remain the same. Interestingly, the final third sees an improvement in their asthma conditions. Why these changes occur varies from person to person and is not entirely understood. Asthma symptoms typically peak during the late second or early third trimester of pregnancy, though flare-ups are rare during labor and the period immediately after birth.

Common symptoms of bronchial asthma include:

Tightness in the chest
Wheezing
Shortness of breath
Coughing

These symptoms can differ in intensity and frequency. They often become worse at night or early in the morning. Factors such as colds, exercise, allergy triggers, weather changes, laughter, or other irritants can set off these symptoms.

During a physical check-up, a person with bronchial asthma may not present any abnormal signs. However, the most common sign is a wheezing sound when they breathe, heard during examination of their lungs. In severe cases of asthma, wheezing may not be present due to significantly reduced airflow, a situation referred to as a “silent chest.”

Testing for Asthma in Pregnancy

Bronchial asthma, like in the wider population, can be diagnosed during pregnancy using a test called spirometry. This test identifies any difficulties with breathing and helps to keep track of how well asthma treatments are working.

There’s a particular test known as the methacholine challenge test, which isn’t recommended during pregnancy. This is because it could trigger a sudden tightening of your airways, making it harder to breathe.

The Asthma Control Test (ACT) is another method of keeping an eye on someone’s asthma while they’re pregnant. This test simply involves answering five questions about how their asthma has affected them in the last four weeks. It helps to measure how well their asthma is under control, with scores ranging from 5 (for badly controlled asthma) to 25 (for completely controlled asthma). If someone scores less than 20, it indicates that their asthma isn’t being controlled effectively.

If a patient’s condition changes and they experience any of the following, it would be considered an asthma flare-up: needing to take more medicine (specifically oral corticosteroids), unexpected visits to the doctor, having to go to the emergency room or being hospitalized.

Treatment Options for Asthma in Pregnancy

The aim of treating asthma during pregnancy is to reduce asthma symptoms, maintain the best possible lung function, and prevent asthma attacks. This not only helps the mother keep her oxygen levels stable but also ensures that the baby receives enough oxygen.

The National Asthma Education and Prevention Program suggests that asthma treatment for pregnant women should be essentially the same as for women who aren’t pregnant. This recommendation is made based on a moderate level of evidence (known as ‘Evidence B’).

For quick relief from asthma symptoms, Salbutamol is the preferred choice due to its proven safety record. Inhaled corticosteroids (ICS) are the go-to medications for long-term asthma control. It’s safe to use ICS, theophylline, and montelukast during pregnancy. However, long-term use of oral steroids has been linked to complications during pregnancy, especially in the first trimester. But, if the need arises, oral steroids can still be used as they would be outside of pregnancy. Again, this advice is backed by a lower level of evidence (Evidence C).

Research indicates that managing asthma during pregnancy, based on symptoms and a measure known as the fraction of exhaled nitric oxide (FENO), can significantly reduce the risk of asthma attacks. For moderate persistent asthma, a long-acting beta 2 agonist teamed up with an inhaled anti-inflammatory medication or an inhaled corticosteroid is the recommended course of treatment. For severe asthma, oral corticosteroids and long-acting beta-agonists are recommended.

Inhaled glucocorticoids are generally safe, but there may be a slight risk of causing hormone and metabolic issues to the fetus. Continued use of oral steroids might heighten the risk of birth complications, such as birth defects, preterm birth, low birth weight, high blood pressure during pregnancy, and gestational diabetes. If anesthesia is needed during labor, regional anesthesia is the preferred choice.

When looking to diagnose asthma during pregnancy, doctors should also consider a variety of other conditions that may show similar symptoms. These include:

GERD (Gastroesophageal reflux disease)
Postnasal drip, which happens when mucus drips from the back of the nose to the throat
Vocal cord malfunction
Hyperventilation syndrome, a condition where you breathe too quickly or too deeply
Pulmonary embolism – a condition in which a blood clot gets lodged in an artery in the lung

Therefore, finding the precise condition requires a careful examination and the consideration of these potential diagnoses.

What to expect with Asthma in Pregnancy

Uncontrolled asthma during pregnancy can lead to complications like low birth weight and preterm birth. However, in most cases, the outlook for pregnant women with asthma is similar to those with asthma who are not pregnant. It’s important for pregnant women diagnosed with bronchial asthma to receive proper evaluation and treatment. The treatment and management of bronchial asthma should be the same in pregnant women as well as nonpregnant individuals.

Possible Complications When Diagnosed with Asthma in Pregnancy

The complications during pregnancy for individuals with bronchial asthma depends on the severity of the asthma and the type of treatment the person is receiving. Asthma flare-ups are often the leading cause of illness and fatalities in both mothers and babies when the mother has bronchial asthma. When asthma is not properly managed during pregnancy, it can lead to several risks and negative outcomes for the baby. These include:

Preeclampsia, a serious condition that involves high blood pressure during pregnancy
Pregnancy-induced high blood pressure
Early labor and premature birth
Birth defects
Low weight at birth
Low blood sugar and seizures in newborns

Asthma can also lead to health problems in expecting mothers, such as:

Respiratory failure, which may require the use of a machine to help with breathing
Barotrauma, an injury to the lungs caused by changes in pressure
Complications due to use of steroid medication

Preventing Asthma in Pregnancy

If you’re pregnant and have asthma, it’s important to get informed about managing your condition. This includes sticking to your prescribed medication, learning how to use an inhaler correctly, and having a written plan to manage your asthma symptoms. You should also learn how to avoid things that trigger your asthma, and if you smoke, you should get help to quit. Every month, you should review and possibly change your asthma medication depending on how well your asthma is controlled. It’s also important to treat any worsening of your asthma symptoms promptly.