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.