Which of the following antibiotics is commonly used to treat UTIs in pregnant women?

Cephalexin is commonly used to treat urinary tract infections (UTIs) in pregnant women because it is a safe and effective antibiotic during pregnancy. This first-generation cephalosporin has a well-established safety profile and is effective against the common pathogens that cause UTIs, such as E. coli and other gram-negative bacteria. It is preferred in this population because it does not pose significant risk to fetal development compared to other antibiotics.

In contrast, ciprofloxacin is typically avoided in pregnant women due to potential risks to fetal development and concerns about cartilage damage. Azithromycin is not the first-line choice for UTIs, as it is more used for respiratory infections and certain sexually transmitted infections. Metronidazole, while useful for certain infections, is not specifically indicated for UTIs and its safety profile in early pregnancy has some concerns. Thus, cephalexin stands out as the most appropriate and safe option among the antibiotics listed for treating UTIs in pregnant women.