Treating asthma during pregnancy safer than not, says new guide

"Poorly controlled asthma in a pregnant woman has unique adverse consequences," Leslie Hendeles, Pharm.D., told Drug Topics. "Asthma attacks may deprive the fetus of oxygen and have been linked to increased prematurity, growth restriction, and other fetal complications." Hendeles, who is a professor of both pharmacy and pediatrics at the University of Florida Colleges of Pharmacy and Medicine, added that asthma leads to increased morbidity and mortality in the mother as well.

According to the ACOG recommendations, it is safer for pregnant women with asthma to be treated with medications than to experience asthma symptoms and exacerbations, and that the main goal of asthma treatment is to maintain sufficient oxygenation of the fetus by preventing hypoxic episodes in the mother. In addition, a step-care therapeutic approach that entails increasing both the number and dosage of medications as asthma severity increases should be utilized by practitioners treating this population.

"There are substantial data on the safety of budesonide during pregnancy from large epidemiology studies in Sweden," Hendeles said. He also pointed out that budesonide is considered a Category B drug, whereas the other ICSs are labeled as Category C.

For pregnant women with moderate persistent asthma, the recommended treatment is a low-dose ICS and salmeterol or a medium-dose ICS and salmeterol if needed. An alternative regimen would be a low- or medium-dose ICS with either a leukotriene receptor antagonist or theophylline to a target serum level of 5 to 12 mcg/ml. Severe persistent asthma requires a high dose of ICS and salmeterol, plus an oral corticosteroid if needed. An alternative regimen includes theophylline in place of the salmeterol. The recommended rescue therapy for all levels of asthma severity is inhaled albuterol.

The new ACOG guidelines also emphasize that avoiding exposure to tobacco smoke and other allergens and irritants can improve maternal well-being and reduce the need for medication. Immunotherapy is recommended for women who are at or near a maintenance dose, who have not had adverse reactions to the injections, and are receiving a clinical benefit. However, women should not begin allergy shots during pregnancy. This is due to the potential for the escalating doses of immunotherapy to cause anaphylaxis during pregnancy, which has been associated with maternal and fetal death. For women with asthma who are breast-feeding, use of prednisone, theophylline, antihistamines, ICS, beta-2-agonists, or cromolyn is not contraindicated.

The guide asserts that optimal management of asthma in order to maintain normal pulmonary function during pregnancy includes objective monitoring of lung function, avoiding or controlling asthma triggers, individualizing pharmacotherapy, and patient education.

Practice Bulletin #90, "Asthma in Pregnancy," was developed based on a review of the best available evidence regarding the management of asthma during pregnancy and was published in the February 2008 issue of Obstetrics & Gynecology.