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 β2-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.