Thorbjørn Lomholt Gregersen, Charlotte Suppli Ulrik

Asthma is a common medical condition complicating pregnancy with potentially serious effects on pregnancy outcome. The aim of this review is to provide an update on efficacy and safety of asthma medications, primarily bronchodilators and corticosteroids, used during pregnancy with focus on pregnancy outcome, and, furthermore, to discuss limitations of available studies and point to possible improvements in future studies. A planned series of systematic searches was conducted using the PubMed database. Use of short-acting β2-agonists has generally been established as safe, and the few studies stating otherwise appear to have, perhaps critical, methodological limitations. The safety of long-acting β2-agonists remains to be further investigated, and the few available studies have methodological limitations and, therefore, provide no definite answers, although a very recent study supports the safety of add-on long-acting β2-agonists to inhaled corticosteroids. Inhaled corticosteroids are generally found to be safe, although further research is needed to investigate both the efficacy and safety of high dose therapy with inhaled corticosteroids. Studies have reported associations between the use of systemic corticosteroids and adverse perinatal outcomes, such as preterm birth, low birth weight, and pre-eclampsia. This must, however, be weighed against the potential serious impact of severe, uncontrolled asthma itself on pregnancy outcome. The main obstacle to a valid interpretation of several of the available studies is the inadequate stratification for asthma severity and control. Overall, asthma in itself and not just poor asthma control poses a greater risk to pregnancy outcomes than asthma medication. Nonetheless, more studies focusing on disentangling the effects of asthma alone and asthma medications are needed. Increased use of stratified risk assessments, taking the concept of asthma severity into greater consideration, is much warranted in future studies.