Asthma is one of the most common health conditions during pregnancy, affecting 1 in 12 women. Asthma can impact your pregnancy, and pregnancy can influence the behavior of your asthma. Asthma, particularly when uncontrolled, has been linked to certain complications of pregnancy, including low infant birth weight and prematurity. Pregnant women with asthma need reliable information to make healthy choices regarding their asthma during pregnancy.
During pregnancy, your breath is your baby’s breath. Oxygen from your lungs enters your blood and circulates to the placenta and then to your baby. If you develop low oxygen levels, for example during an asthma attack, it could affect your baby’s development.
Your asthma may start to behave differently due to pregnancy-related hormonal and immune system changes that occur in your body during your pregnancy. For some women, asthma can improve, worsen, or behave as usual. A checkup by your asthma doctor if you are trying to conceive, and regular asthma monitoring while you are pregnant is recommended. If your asthma has been difficult to control, you may need close monitoring. Measurement of exhaled nitric oxide (eNO) in your breath (a substance produced in airways from inflammation present in uncontrolled asthma) can be used to adjust your asthma medicine and optimize asthma control during pregnancy. In one study, when pregnant women had regular monitoring and medicine adjustment based on eNO, they used less medicine, were less likely to have an asthma attack or be hospitalized for asthma, and had good pregnancy outcomes. This test can typically be done by an allergist or pulmonologist.
Up to 1/3 of pregnant women stop their usual asthma treatment during pregnancy without consulting their doctors. Up to 1/4 of non- asthma specialists advise women to stop or reduce asthma medicines because they lack knowledge about the impact of uncontrolled asthma on a pregnancy. As a result, 20 percent of pregnant women with asthma have an attack during pregnancy, putting their pregnancy at risk. These attacks are largely preventable, and strong evidence supports that common asthma medicines that prevent these types of attacks are safe to use during pregnancy. A study in Sweden found healthy outcomes for thousands of women with asthma treated with inhaled budesonide (Pulmicort). Although we have the most safety information for budesonide, similar safety profiles have been found for other asthma medicines. If your asthma is under good control, stopping or changing medicine during pregnancy is not recommended. In one study, pregnant women with mild asthma on no medicine had children with lower birth weight than women with more severe asthma treated with asthma medicines. The take-home message is that even mild asthma, if not controlled, can impact pregnancy more than medicines used to treat asthma. Talk to your doctor before making any changes in your asthma medicine during pregnancy. For more information about safe medicine use during pregnancy, go to http://www.mothertobaby.org.
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Linda Rogers, MD, is an Associate Professor in the Pulmonary, Critical Care and Sleep Medicine Division of the Icahn School of Medicine at Mount Sinai, and Director of the Clinical Asthma Program. She is a member of the multidisciplinary team of the Mount Sinai – National Jewish Health Respiratory Institute.
References
Olesen et al A population-based prescription study of asthma drugs during pregnancy; changing the intensity of asthma therapy and perinatal outcomes. Respiration 2001;68(3):256-61.
Powell et al. Management of asthma in pregnancy guided by measurement of fraction of exhaled nitric oxide: a double-blind, randomised controlled trial. Lancet 2011 Sep 10;378(9795):983-90.
Cossette et al. Impact of maternal use of asthma-controller therapy on perinatal outcomes. Thorax. 2013 Aug;68(8):724-30