What antimicrobial agent is contraindicated during pregnancy for bacterial infections?

Fluoroquinolones are contraindicated during pregnancy due to potential risks for the developing fetus. This class of antimicrobial agents has been associated with concerns regarding cartilage development and possible effects on the musculoskeletal system of the fetus. Animal studies have indicated adverse effects, leading to recommendations against their use during pregnancy unless the benefits significantly outweigh the risks.

In contrast, the other classes of antibiotics mentioned have been studied more extensively and are generally considered safer options during pregnancy. Macrolides, such as azithromycin and erythromycin, are often used for various bacterial infections as they have not shown the same level of risk. Penicillins and cephalosporins are also commonly prescribed during pregnancy because they are well-tolerated and have a long history of safety for both the mother and the fetus. Thus, fluoroquinolones stand out as the inappropriate choice among these options for treating bacterial infections during pregnancy.