The same 16-week pregnant patient. Which local anesthetic is contraindicated (best avoided) in this patient?

Correct answer: A. Articaine 4%

• A. Correct (keyed). Among these, articaine 4% is the one guidance most often says to AVOID in pregnancy (FDA category C and a 'pump-and-dump' caution while nursing); lidocaine is the preferred safe choice.
• B. Lidocaine is Category B and the anesthetic of choice in pregnancy.
• C. Mepivacaine is Category C but may be used with caution.
• D. Prilocaine is Category B but carries a methemoglobinemia caution; still generally considered acceptable.

Note: Sources vary: some consider articaine acceptable in pregnancy. It is keyed here because several references list articaine as the agent to avoid/use with most caution; lidocaine remains the safest choice.