We demonstrated that asthma remains a common condition among pregnant women and that the prevalence of self-reported asthma in the United States is between 8.4% and 8.8%. In addition, approximately 4.1% of all pregnant women experienced an asthma attack in the previous year. Prevalence rates in other countries seem to be higher or substantially lower; however, further characterization of international trends using nationally representative data is needed. Data from a large prospective cohort study in the northeastern United States and national data demonstrate continued opportunities for population-level improvement in well-managed asthma during pregnancy. Finally, asthma diagnosis and asthma control seem to differ by population characteristics (eg, age, race/ethnicity, socio-economic status), and further research and clinical involvement are needed to ad-dress potentially systematic variation in reporting and management of the disease.