Asthma Drug Birth Defect Risk Seen When Used in Pregnancy: Study

A new study suggests a link between specific birth defects and asthma medication use during pregnancy, raising concerns about the safety of popular drugs like Advair and Symbicort among expectant mothers. 

According to a report published last week in the medical journal Pediatrics, research funded by the New York Center for Environmental Health found that the use of anti-imflammatory and bronchodilator drugs, alone or in combination, appeared to increase the risk of some rare birth defects by as much as 300% or more in some cases.

Researchers mined the National Birth Defects Prevention Study for data on 2,853 infants born with birth defects and 6,726 infants born without defects. Looking at cases where the mother was exposed to anti-inflammatory, bronchodilator asthma drugs or both, they found three specific types of rare birth defects that appeared to increase in prevalence. However, the researchers were unable to find any link between most common birth defects.

Women who used bronchodilators had more than double the risk of giving birth to a child with isolated esophageal atresia; a congenital birth defect where the esophagus fails to connect all the way to the stomach, requiring major surgery if the child is to survive. Women using anti-inflammatory asthma drugs during the first trimester had more than double the risk of giving birth to an infant with isolated anorectal atresia, in which the rectum or anus does not have a sufficient opening. For expecting mothers who took both types of asthma drugs combined, there was a more than 300% increased risk of giving birth to a child with omphalocele, an abdominal wall defect where some organs, including the intestines, liver and others, develop on the outside of the belly button.

Anti-inflammatory asthma drugs are typically inhaled corticosteroids like Flovent and Pulmicort. Brtonchodilators used for asthma include Albuterol and Combivent. The two types of drugs are used in combination in products including Advair and Symbicort.

The researchers found no association with other types of birth defects. They also noted that their findings could be due to numerical aberrations or that the birth defects could be caused by the severity of the mother’s asthma and related lack of oxygen to the developing fetus.