Healthcare utilisation by pregnant patients with asthma in South Korea: a cohort study using nationwide claims data

Objectives: Few nationwide population-based studies have examined the burden of asthma during pregnancy. Here, we investigated the burden and medical treatment of asthma during pregnancy requiring healthcare utilisation in South Korea. Design: Cohort study. Setting: Nationwide insurance claims database. Participants: A total of 1 306 281 pregnant women who delivered in South Korea in 2009-2011. Outcomes: The prevalence and exacerbation rates of asthma requiring healthcare utilisation, and the prescription of antiasthmatic drugs during pregnancy. Results: The prevalence of asthma requiring healthcare utilisation was 0.43% among pregnant women. Among those with asthma requiring healthcare utilisation, 6.9% were hospitalised and treated with systemic steroids and short-acting beta(2)-agonists during pregnancy. Oral drugs were prescribed less during the third trimester than during the first trimester (all p values for trends were < 0.001). A significant number of patients with asthma were likely to stop taking antiasthmatic drugs after becoming pregnant. Conclusions: The prevalence of asthma requiring healthcare utilisation during pregnancy was not very high. However, a significant number of women were likely to stop taking antiasthmatic drugs, and those who did tended to experience exacerbations.