Asthma Prevalence among Pregnant and Childbearing-aged Women in the United States: Estimates from National Health Surveys

PURPOSE: Asthma is a major complication of pregnancy, but there are currently no reliable national estimates for the United States of asthma prevalence in pregnancy or in the childbearing years. METHODS: The prevalence of asthma among pregnant women and all childbearing-aged women was estimated and examined by age group using the National Health Interview Survey (NHIS), 1997–2000, the Behavioral Risk Factor Surveillance System (BRFSS), 2000–2001, and the Third National Health and Nutrition Examination Survey (NHANES III), 1988–1994. Time trends were explored using NHANES II (1976–1980) and NHANES III (1988–1994). RESULTS: Asthma was estimated to affect from 88,573 to 190,650 pregnant women between 1997 and 2001, or approximately 3.7% to 8.4% of pregnant women in the United States. A slightly lower estimate of 3.2% was obtained for the period between 1988 and 1994. Among adult women of childbearing age, a two-fold increase in asthma from 2.9% to 5.8% occurred between 1976–1980 and 1988–1994. Among women aged 18 to 24, the increase was three-fold, from 1.8% to 6.0%. CONCLUSION: The prevalence of asthma during pregnancy may be higher than previously estimated and appears to be continuing to increase.