Maternal asthma in pregnancy has been associated with an increased risk of adverse outcomes, including preeclampsia, low birth weight, preterm birth and congenital abnormalities. This, compounded with the increasing prevalence of asthma in the general population, emphasizes the need for optimal asthma control during pregnancy. Of the associated adverse risks, there has not been a clear consensus as to whether the increased risk of congenital abnormalities is related to asthma itself or the medications used to treat asthma. A recent study in the Journal of Allergy and Clinical Immunology sought to identify whether this risk is associated with asthma medications in the first trimester.1
What is the underlying cause?
The study did find that there was an increased chance of congenital abnormalities including cleft palate and gastroschisis in those with exposure to inhaled B2 agonists (e.g. albuterol), the drug typically found in rescue inhalers. Though there is an increased risk, the individual risk remains low – less than 1 in 100 births. There was no increased risk seen with inhaled corticosteroids, which are often used in controller inhalers.
Despite these findings,both maternal asthma and asthma exacerbations during the first trimester of pregnancy have been found to increase the risk of congenital anomalies as well.http://www.jacionline.org/article/S0091-6749(08)00521-6/pdfFurthermore, asthma exacerbations during pregnancy have been associated with other unfavorable pregnancy outcomes for both the mother and infant.The study highlights these facts as the risks of uncontrolled asthma might be much greater than the studied specific risks. Ultimately, the study suggests that the use of prophylactic inhaled steroids seems to be the best approach for treating asthma in pregnancy to prevent asthma exacerbations and to reduce the need for β2-agonists. For this reason, both those pregnant or considering pregnancy that have asthma would benefit from being followed by an asthma specialist.
By Dr. Michael Alvares
Allergy Partners of Dallas-Fort Worth
1. Garne et al. Use of asthma medication during pregnancy and risk of specific congenital anomalies: A European case-malformed control study. J Allergy Clin Imuno. Vol 136, Number 6. pp 1496-1502.