Asthma and reproductive outcomes: A Danish nationwide cohort study

<bold>Background:</bold> Asthma is common among women of reproductive age. Prior studies revealed associations between asthma and fertility by reporting prolonged time to pregnancy and altered fecundability. <bold>Aim:</bold> Investigate fertility in women treated with anti-asthmatic drugs (ICS/LABA/LAMA/SABA/LTRA) compared to non-asthmatic controls. <bold>Method:</bold> All Danish women born 1976 to 1999 were followed from 1994 to 2017. Asthma was identified by repeated redemption of anti-asthmatic drugs with severity per 2018 GINA guidelines. Outcome were fertility treatment, compared to controls applying a Cox regression model adjusted for age, calendar year, and education. <bold>Results:</bold> In total, 769,880 were included and followed (median time of 10.8 years [IQR 5.3-17.5]). The proportion who gave birth in follow-up was 77%, irrespective of asthma exposure. However, women with asthma experienced higher degree of fetal loss (17.0% vs. 15.7%) and more use of fertility treatment (5.6% vs. 5.0%) compared to controls. Risk of fertility treatment was significantly higher in women with asthma: HR 1.12(1.08-1.15). GINA step 4-5 had the highest risk of needing fertility treatment: HR 1.62(1.43-1.83) and women with ≥ 3 prior exacerbations had an increased risk of needing fertility treatment: HR 1.38(1.19-1.60). <bold>Conclusion:</bold> Although women with asthma more often require fertility treatment, a risk correlated to asthma severity and exacerbations, asthma does not seem to affect the number of live births. <fig><object-id>erj;64/suppl_68/OA5579/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>