Short-acting asthma medications lower female fertility

Michael Schatz, MD, MS

Many studies have suggested that women with asthma are at increased risk for a number of pregnancy complications, ranging from miscarriage to preeclampsia to prematurity to birth defects in the infant. A substantial number of studies have also suggested that milder or better controlled asthma is associated with less of these risks than more severe or uncontrolled asthma. In these studies severity and control were assessed by symptoms, exacerbations or pulmonary function. Although asthma medications could also potentially be responsible for some of the increased risks, studies of the safety of commonly used asthma medications, such as inhaled corticosteroids and short and long-acting beta agonist bronchodilators, have generally been reassuring. This has led to the guideline recommendations that the primary goal of treating asthma during pregnancy is to control the asthma, and that the risk of the uncontrolled asthma to the mother and the baby is greater than the risk of appropriate asthma medications.

The study by Grzeskowiak and colleagues   from the international Screening for Pregnancy Endpoints (SCOPE) study adds fertility to the list of outcomes for women that appear to be affected by asthma control.  In this study, women treated with beta agonists only experienced a longer time to pregnancy than women on asthma controllers, suggesting to the authors that better treated and controlled patients had improved fertility compared to patients on rescuer therapy only. This interpretation would be consistent with the pregnancy data described above. It should be noted, though, that the previously published pregnancy data assessed severity and control directly (symptoms, exacerbations, pulmonary function), while in the SCOPE study, inferences regarding control were made from treatment being taken. It is possible that some patients on rescue therapy only had mild, intermittent asthma that didn’t require controllers and that some patients on controllers were actually not well-controlled.

To be sure of the relationship between better asthma control and improved fertility, further studies of time to pregnancy in which asthma control is measured directly will be necessary. In the meantime, this study does potentially add one more reason to optimally manage and control asthma in women who want to become pregnant and supports the use of inhaled corticosteroids ± long-acting beta agonists when appropriate in such patients.

Tania Elliott, MD, FAAAAI, FACAAI

This study highlights the importance of appropriate asthma diagnosis and management.

While the study suggests that short acting beta agonists may be the underlying cause of delayed fertility, it is not clear whether it was the medication itself, or if the fertility rates may be related to poor asthma control. The absence of lung function studies and classification of asthma severity contributes to these limitations.

An important takeaway from this study for primary care physicians is that asthma severity and even more importantly from a risk factor perspective, asthma control, should be addressed with all patients, and for women of child bearing age, desire to conceive should also be addressed in this context. This study also sheds light on the importance of proper asthma classification and treatment during the pre-conception phase, particularly as it is well established that 30% of women with asthma have a flare of symptoms during pregnancy. Identification of asthmatic triggers is also important to address with the patient and should be considered as a key part of treatment, particularly as avoidance is truly medication free.