Which antibiotics are avoided during pregnancy due to teratogenic risks?

• A. Penicillins
• B. Cephalosporins
• C. Tetracyclines and fluoroquinolones
• D. Macrolides

Answer: (C)

In pregnancy, selecting antibiotics aims to protect fetal development, so drugs with proven teratogenic risks are avoided. Tetracyclines cross the placenta and deposit in developing teeth and bone, leading to permanent tooth discoloration and enamel defects, and they can interfere with bone growth. Fluoroquinolones likewise pose concerns for fetal cartilage and joint development, with animal data showing potential arthropathy and limited human safety data. Because of these risks, these two classes are avoided during pregnancy. Other common classes, like penicillins and cephalosporins, have well-established safety records for use in pregnancy, and macrolides are used when needed, so they do not carry the same teratogenic concerns.