Certain bronchodilators are used to treat asthma in pregnant women, including albuterol, bitolterol, formoterol, metaproterenol and salmeterol. Although there have been no studies on birth defects in humans, and no reported cases definitively linking birth defects to bronchodilators, some animal studies involving bronchodilators report birth defects when given in doses many times higher than human doses.

Pregnant women who were given epinephrine under the skin have had more birth defects than expected in some studies, although the severity of the mother’s asthma may have contributed to this result.

The medicines fenoterol, isoproterenol, pirbuterol, procaterol and terbutaline have not been shown to cause birth defects in animal studies. Women taking bronchodilators who are pregnant or wish to become pregnant are encouraged to discuss potential benefits and risks with their physician.

It is not known at this time whether bronchodilators pass into the breast milk. Although most medicines pass into breast milk in small amounts, many of them are considered safe for nursing infants. Mothers who use bronchodilators and who wish to breastfeed are encouraged to discuss this with their physician.