Avoid prescribing macrolides to pregnant women, say UK researchers after they found the antibiotics were associated with an increased risk of significant birth defects, particularly cardiac defects.

The study is certainly going to cause some concern as to date macrolides such as erythromycin, clarithromycin and azithromycin are commonly prescribed here in Australia especially to patients who are allergic to penicillin. And given their category A pregnancy safety rating in this country, many GPs would not have thought twice about writing a script for any of these antibiotics for women who were, or potentially were, pregnant.