Maternal asthma, asthma medication use, and the risk of congenital heart defects

Asthma is a common problem that complicates pregnancy. Several drugs are considered acceptable for use during pregnancy, although none have been classified as safe. Few studies have assessed the health impact of maternal asthma/medication use on the fetus.

A population-based case-control study was conducted in New York State to determine if cardiac congenital malformations in offspring were associated with maternal use of asthma medication and/or maternal asthma. Cases were cardiac anomalies in the New York State Congenital Malformations Registry. Controls were live births without any major birth defects randomly selected from birth certificates and frequency matched by year of birth. Data were collected through a 30 min telephone interview. Exposure was maternal asthma/medication use, maternal asthma/no medication use, no asthma/medication use, and no asthma/no medication use (reference).

A total of 502 (59.4%) cases and 1,066 (53.8%) controls participated. A positive association was seen between any heart defect and women with asthma who used medication (OR 2.38; 95% CI: 1.18, 4.82). No significant associations were observed between heart defects and either women with asthma who did not use medication or women without asthma who used asthma medications. When considering types of medication used, offspring of women with asthma who used bronchodilators had an increased risk of any heart defect (OR 2.20; 95%CI: 1.05, 4.61).

These results suggest that both maternal asthma status (controlled vs. uncontrolled; severe vs. mild) and asthma medication use, particularly bronchodilators, may play a role in cardiac malformations in offspring.