© 2015 American College of Chest Physicians. BACKGROUND: A multicenter study in the late 1990s demonstrated suboptimal emergency asthma care for pregnant women in US EDs. After a decade, follow-up data are lacking. We aimed to examine changes in emergency asthma care of pregnant women since the 1990s. METHODS: We combined data from four multicenter observational studies of ED patients with acute asthma performed in 1996 to 2001 (three studies) and 2011 to 2012 (one study). We restricted the data so that comparisons were based on the same 48 EDs in both time periods. We identified all pregnant patients aged 18 to 44 years with acute asthma. Primary outcomes were treatment with systemic corticosteroids in the ED and, among those sent home, at ED discharge. RESULTS: Of 4,895 ED patients with acute asthma, the analytic cohort comprised 125 pregnant women. Between the two time periods, there were no significant changes in patient demographics, chronic asthma severity, or initial peak expiratory flow. In contrast, ED systemic corticosteroid treatment increased significantly from 51% to 78% across the time periods (OR, 3.11; 95% CI, 1.27-7.60; P = .01); systemic corticosteroids at discharge increased from 42% to 63% (OR, 2.49; 95% CI, 0.97-6.37; P = .054). In the adjusted analyses, pregnant women in recent years were more likely to receive systemic corticosteroids, both in the ED (OR, 4.76; 95% CI, 1.63-13.9; P = .004) and at discharge (OR, 3.18; 95% CI, 1.05-9.61; P = .04). CONCLUSIONS: Between the two time periods, emergency asthma care in pregnant women signifi cantly improved. However, with one in three pregnant women being discharged home without systemic corticosteroids, further improvement is warranted.