Evaluating inhaled corticosteroid use among pregnant women with asthma: systematic review and meta-analysis

Background: Studies demonstrate that the rate of prescriptions for ICS decreases in early pregnancy suggesting that some women cease their medication. However, this could also be related to non-adherence to prescribed asthma medication. ICS use during pregnancy has not previously been summarised in a systematic review. Objective: The aim of this systematic review and meta-analysis was to evaluate ICS use during pregnancy among women with asthma. Methods: We performed a systematic search of literature using terms related to asthma, pregnancy and medication use. All English articles reporting asthma medication use among pregnant women with asthma were included (n=55). Prevalence and changes in ICS use during pregnancy were pooled using STATA (version 15.0, StataCorp USA). Results: The pooled prevalence of ICS use during pregnancy was 39% (95%CI 35-43%). The prevalence of ICS use was highest in Europe (45%, 95%CI 39-51%), followed by Australia (39%, 95%CI 32-47%) and North America (33%, 95%CI 27-39%). In eight prescription databases, ICS prescription rates lowered in the first trimester of pregnancy, compared to pre-pregnancy, increased in the second trimester, and decreased in the third trimester. Seven studies reported asthma medication adherence among pregnant women, using six differing measures of self-reported non-adherence. In two comparable studies, pooled ICS non-adherence was 40% (95%CI 36-44%). Conclusion: The prevalence of ICS use among pregnant women with asthma is 39%, and prescription rates for ICS change throughout pregnancy. ICS non-adherence among pregnant women with asthma is high and needs urgent attention.