Supporting evidence for safety of asthma combination therapy during pregnancy

Published Online: September 14, 2014

Asthma is one of the most common serious diseases among women of childbearing age, affecting around 4%–12% of pregnant women. Severe or uncontrolled asthma can increase the risk of pregnancy complications affecting the mothers and their newborns compared to controlled asthma. The goal of asthma therapy - as the guidelines recommend - is to maintain optimal control of asthma symptoms and prevent acute asthma exacerbations. Among the important clinical decisions that physicians must make if asthma cannot be controlled with a low dose of inhaled corticosteroid (ICS) during pregnancy is whether to prescribe long-acting inhaled beta2-agonist (LABA) to supplement the current dose of ICS or to increase the dose of ICS. However, there has been no direct comparison of these treatment regimens to guide physicians in whether it is safer for the newborn to increase the dose of ICS during pregnancy or to add a LABA.

In an article recently published in The Journal of Allergy and Clinical Immunology (JACI), S. Eltonsy and colleagues present a comparative safety study where they examined the major malformations prevalence of two widely used treatment options for persistent asthma during pregnancy. The authors of the study compared the risk of major congenital malformations in pregnant asthmatic women treated with a combination of LABA and ICS and those treated with a higher dose of ICS monotherapy. They used data from asthmatic pregnant women and their children recorded in the administrative health databases of Quebec, Canada between 1990 and 2009.

In order to obtain unbiased results, the researchers divided the asthmatic women into two groups based on the asthma medications they used to control their symptoms. In the first group, women who used LABA plus low-dose ICS were compared to those who used a medium-dose ICS monotherapy and in the second group, women who used LABA plus medium-dose ICS were compared to those who used a high-dose ICS monotherapy. The researchers used the hospital-based diagnostic codes recorded in the databases to identify the major congenital malformations that occurred at birth or during the first year of life of the infant. The authors paid attention to important risk factors of congenital malformations like the mothers’ age and chronic diseases other than asthma, and also considered the maternal asthma severity and control.

For the analysis, the authors included 1302 pregnancies in the two groups of asthmatic women, with an overall major malformations prevalence of 7.4%. With this design, the authors were able to compare treatments that have similar indications in each group. The researchers found that the risk of major malformations did not differ when a combination therapy of LABA plus ICS or a higher dose of ICS monotherapy was used in the first trimester of pregnancy. They found that the risk was not higher among combination therapy users in both groups of asthmatic women (i.e. moderate and the severe asthmatic pregnant women).

The authors concluded that their findings support the fetal safety of LABA with ICS combination in the management of persistent asthma during pregnancy, encouraging clinicians to prescribe either combination or ICS monotherapy to keep the mothers’ asthma under control. These reassuring results are consistent with asthma management guidelines, and provide scientific evidence that help physicians and mothers. The authors declared the results as encouraging for asthmatic women to continue taking their asthma medications when required to control their asthma symptoms during pregnancy, and therefore increasing the likelihood of healthy pregnancies and newborns.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.


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