Poorly Controlled Asthma During Pregnancy Remains Common in the United States

Background: Asthma is among the most common preexisting medical conditions in pregnancy. Uncontrolled asthma may increase the risk of adverse pregnancy outcomes.

Objectives: To describe the prevalence, severity, and control of asthma during pregnancy in the United States.

Methods: We identified 2 cohorts of pregnancies ending in a live birth within 2 large US health care claims databases: the Truven Health MarketScan Commercial Claims and Encounters Database (MarketScan, private insurance) for the period 2011 to 2015 and the nationwide Medicaid Analytic eXtract (MAX, public insurance) for the period 2000 to 2013. We defined asthma prevalence, severity, and control on the basis of International Classification of Diseases, 9th Revision diagnoses and asthma-related treatments. Severe asthma was defined as dispensing of 1 or more medium/high-dose inhaled corticosteroid plus additional therapy within the 12 months preceding delivery. Poor control was defined as having at least 1 of the following: 1 or more exacerbation (asthma-related hospitalization or emergency room visit, or a course of oral corticosteroids) or 5 or more filled prescriptions for short-acting β-agonists between the last menstrual period and delivery.

Results: Among 604,420 pregnant women in MarketScan and 2,071,359 in MAX, 20,104 (3.3%) and 120,745 (5.8%) had asthma, respectively. Among pregnant women with asthma, 19.0% and 18.8% had severe asthma and 16.5% and 28.0% had poorly controlled asthma in MarketScan and MAX, respectively. Many women with poorly controlled asthma during pregnancy were not dispensed a long-term controller (38.4% in MarketScan and 43.3% in MAX). Within both cohorts, women with poor control were more often smokers and obese, had more comorbidities, and used more concomitant nonasthma medications.

Conclusions: Poorly controlled asthma is more frequent among publicly versus privately insured pregnancies in the United States. Dispensing of long-term controller medications during pregnancy remains low, even for symptomatic patients.