Which class of medication is teratogenic and should be avoided in pregnancy?

• A. ACE inhibitors/ARBs
• B. Beta-blockers
• C. Hydralazine
• D. Nitrates

Answer: (A)

ACE inhibitors and ARBs are teratogenic because they disrupt the fetal renin-angiotensin system, which is crucial for kidney development and the production of amniotic fluid. By blocking angiotensin II signaling, these drugs reduce fetal kidney perfusion and urine output, leading to oligohydramnios, renal dysplasia, and potential fetal demise or neonatal renal failure. The risk exists throughout pregnancy, with particularly serious effects if exposure occurs in the later stages. For this reason, they are contraindicated in pregnancy. If antihypertensive therapy is needed during pregnancy, safer options include labetalol, methyldopa, or nifedipine, with careful fetal monitoring and prompt discontinuation if exposure has occurred.