Asthma in Pregnancy
Asthma is a chronic airway inflammatory disease that affects about 4 to 8 percent of all pregnant women. Asthma is a chronic condition associated with obstruction of the airways of the lungs produced by spasm of the muscles, increased production of mucous and swelling of the airways due to an inflammatory response. The disease is episodic and is usually short-lived, lasting minutes to a few hours. The common symptoms of asthma include a sensation of tightness in the chest, wheezing, shortness of breath, coughing and sometimes chest pain.
How pregnancy affects women with asthma
It is uncertain what one can expect when a woman with asthma becomes pregnant. Statistics show that approximately 1/3 of women will get better, 1/3 will remain the same, and 1/3 may worsen. Studies have shown the following patterns:
- Women with severe asthma are at higher risk to worsen while pregnant, while women with mild asthma tend to see their asthma improve.
- If a woman has her asthma worsen with one pregnancy, she is more apt to have a worsening of her asthma with subsequent pregnancies.
- Weeks 24 to 36 of pregnancy are the highest range for the asthma to get worse, with less than 10 percent having problems with labor and delivery.
- After delivery, asthma patterns usually return to what they were like before the pregnancy.
Pregnancy usually does not increase the respiratory rate and capacity of the lungs. A pregnant woman experiences elevation of the diaphragm due to growth of the baby, changes the tidal volume, oxygen uptake and residual volume of air. Asthma leads to an inflammatory response with reduction in airway diameter, edema and thick secretions.
How severe asthma can affect a pregnancy
Although women with mild asthma rarely have problems, women with severe asthma are at risk of problems with their pregnancy including:
- Pregnancy-induced hypertension and/or preeclampsia
- Premature labor and/or birth
- Fetal growth restriction
- Uterine hemorrhage
- Low birth weight
- Neonatal low blood sugar, seizures, increased heart rate and the need for the baby to be in the neonatal intensive care center
- Respiratory failure
Factors that can bring on an asthma attack
Asthma seems to be a complex interaction of genetic predisposition and stimulation from many factors including the following:
- Allergens – pollens, animal dander, dust mites, molds, spider bites and cockroaches
- Environmental irritants – air pollution, wood smoke, cigarette smoke, odors such as perfumes, chemicals and dust
- Drugs and chemicals – aspirin, nonsteriodal anti-inflammatory agents, radioconstrast agents, sulfites and beta blockers
- Medical conditions – upper respiratory infections, sinusitis, reflux
Treatments for pregnant asthmatic patients
Almost all of the anti-asthma drugs have been safely used during pregnancy. Outpatient management of asthma is similar for women who are pregnant and those who are not. Inhalers and corticosteroids are used in the acute and outpatient setting.
If you have asthma and become pregnant, be sure to discuss this with your obstetrician. Talk about the signs and symptoms of an attack, safety of the medications you are taking and when you should seek emergency treatment.