NEW YORK (Reuters Health) – Most asthma medications used during pregnancy have little or no adverse effect on the developing fetus, new research shows. The possible exception is cromone agents, which may increase the risk of musculoskeletal defects.

“Management of asthma with medications during pregnancy in accordance with the current guidelines appears to be safe overall,” Dr. L. J. Tata, from City Hospital in Nottingham, UK, and colleagues write. “However, older cromones may carry a moderate teratogenic risk and their use in pregnancy should be cautioned.”

As reported in the November issue of Thorax, Dr. Tata’s team assessed in utero asthma medication exposure in 5124 children with congenital malformations and in 30,053 controls, matched by birth year, general practice, and singleton or twin delivery. Data on medication usage during pregnancy was available as part of the Health Improvement Network primary care database.

Children born to asthmatic mothers were 10% more likely to have a malformation than those born to non-asthmatic mothers. Further analysis, however, indicated that this was not due to use of asthma medications.

In utero exposure to short- or long-acting beta agonists, inhaled corticosteroids, oral corticosteroids, other bronchodilators, or cromones had no impact on the overall risk of malformations.

However, in looking in more detail, the authors found that cromone exposure raised the odds of musculoskeletal system malformations by 9.38-fold (p = 0.002). Still, the authors urge caution in interpreting this finding since it was based on only five exposed cases.

In an accompanying editorial, Dr. Mario Cazzola, from the University of Rome, and Dr. Maria Gabriella Matera, from Second University of Naples, Italy, comment that because the risks of uncontrolled asthma during pregnancy “are greater than those of the adverse effects caused by controller medication use, we strongly support the opinion that women with asthma should receive controller therapy during pregnancy.”

Reference:
Thorax 2008;63:944-945,981-987.