Asthma health services utilisation before, during and after pregnancy: a population-based cohort study.

During pregnancy, females with asthma may be at higher risk of exacerbation. The objective of this study was to determine whether females with asthma in Ontario, Canada have increased health services utilisation (HSU) during pregnancy.Rates of asthma-specific, asthma-related and non-pregnancy-related HSU were calculated in a population-based cohort of pregnant females with asthma. Poisson regression with repeated measures was used to determine adjusted rate ratios and 95% confidence intervals of HSU during and 1 year after pregnancy, compared to the year before pregnancy.The cohort consisted of 103 976 pregnant females with asthma. Compared to the year prior to pregnancy, hospitalisation rates per 100 person-months during pregnancy increased 30% for asthma (from 0.016 to 0.020), 24% for asthma-related conditions (from 0.012 to 0.015) and decreased 37% for non-pregnancy-related conditions (from 0.24 to 0.15). Emergency department visits for asthma and asthma-related conditions did not increase significantly during pregnancy. During pregnancy, physician office visits decreased 19% for asthma (from 2.20 to 1.79), 10% for asthma-related conditions (from 9.44 to 8.47) and increased 74% for non-pregnancy-related conditions (from 56.4 to 98.2).Hospitalisations for asthma and asthma-related conditions increased during pregnancy, demonstrating that the overall increase in non-pregnancy-related physician office visits may not meet the primary care needs of pregnant females with asthma.