Albuterol may not be safe for women who are pregnant. In animal studies that looked at the effects of albuterol during pregnancy, the drug caused birth defects.
Albuterol and Pregnancy Category C
The U.S. Food and Drug Administration (FDA) uses a pregnancy category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category C is given to medicines that have not been studied in pregnant humans, but do appear to cause harm to the fetus in animal studies. Also, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.
Albuterol was given a pregnancy Category C rating because of potential problems in animal studies. When albuterol was given to pregnant mice, it caused birth defects, especially a cleft palate. In rabbits, albuterol caused brain and skull problems. In humans, albuterol can increase the heart rate and blood sugar levels in the fetus.
However, it is important to note that animals do not always respond to medicines in the same way that humans do. A pregnancy Category C medicine may be given to a pregnant woman if the healthcare provider believes that the benefits to the pregnant woman outweigh any possible risks to the unborn child. Because "rescue" medications like albuterol are usually essential for people with
asthma, healthcare providers typically recommend that pregnant women continue to take albuterol. Several references state that albuterol is compatible with pregnancy. In fact, albuterol is sometimes used to treat premature labor, usually without causing any problems in the fetus.