Among women with asthma who become pregnant, one-third will see an improvement in asthma symptoms, one-third will see their asthma worsen, and one-third will not notice much of a difference. Asthma control during pregnancy tends to be related to pre-pregnancy asthma control. Twenty percent to 35% of pregnant women will experience an asthma exacerbation during pregnancy. The following trends among pregnant asthmatics have also been noted:
- Asthma is less severe over the last 4 weeks of pregnancy.
- Among women whose asthma improves during pregnancy, the improvement occurs gradually throughout the pregnancy.
- Worsening of asthma among pregnant women was most common from weeks 29 to 36 of pregnancy.
- Asthma exacerbations are not common during labor and delivery.
- In subsequent pregnancies, the severity of asthma tends to stay about the same.
One risk factor for worsening asthma during pregnancy may be stopping medication when finding out that you are pregnant. Among women who stay on inhaled steroids from the beginning of pregnancy, less than 5% developed an acute asthma attack compared to nearly 20% of women who were not on inhaled steroids at the time of pregnancy.
Making sure your asthma is well controlled before getting pregnant, taking your medication regularly, and making sure you tell your doctor as soon as you become pregnant are all important strategies for keeping you asthma under control during pregnancy.
Sources:
Murphy VE, Gibson P, Talbot PI, Clifton VL. Severe asthma exacerbations during pregnancy. Obstet Gynecol. 2005 Nov;106(5 Pt 1):1046-54.
Schatz M, Harden K, Forsythe A, et al. The course of asthma during pregnancy, post-partum and with successive pregnancies: a prospective analysis. J Allergy Clin Immunol 1988; 81: 509-517.
UpToDate. www.uptodate.com. Accessed March 15, 2009. Physiology and clinical course of asthma in pregnancy.
B S Stenius-Aarniala, J Hedman and K A Teramo. Acute asthma during pregnancy. Thorax 1996;51:411-414.
