Final answer:
Tetracycline is avoided when treating an infection in pregnant women because it influences the fetus' teeth buds.
Step-by-step explanation:
Tetracycline is avoided when treating an infection in pregnant women because it influences the fetus' teeth buds. Tetracycline can cause permanent discoloration of developing teeth in fetuses, leading to a condition called dental staining. This is why it is not recommended during pregnancy.