ACE Inhibitors
Is It Safe to Take ACE Inhibitors or ARBs During Pregnancy?
Key takeaways:
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are medications commonly used to treat high blood pressure. But they should be avoided during pregnancy due to potential harm to the growing fetus.
If you’re taking an ACE inhibitor or ARB and find out you’re pregnant, tell your healthcare provider right away. They’ll help you find a safer treatment option.
There are other blood pressure medications that are considered safer to use during pregnancy. Examples include labetalol, methyldopa, and nifedipine.
Not all medications are safe to take when you’re pregnant. If you’re planning for pregnancy, you’ll want to look through your medicine cabinet to make sure everything you’re taking is safe to take while pregnant. And this includes your prescription medications, too.
If you have chronic high blood pressure (hypertension), you may be taking medications to manage it. But some high blood pressure medications can actually harm the growing fetus if taken during pregnancy. Two common classes to avoid are angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs).
ACE inhibitors are a class of medications that work by stopping your body from making a chemical that causes your blood vessels to tighten. This helps your blood vessels relax, which lowers your blood pressure.
Examples of ACE inhibitors include:
Lisinopril (Zestril, Prinivil)
Benazepril (Lotensin)
Enalapril (Vasotec)
Ramipril (Altace)
Quinapril (Accupril)
ARBs are medications that work very similarly to ACE inhibitors. But instead of stopping the chemical from being made, they block its receptor (binding site) in your body. This results in a similar blood pressure-lowering effect.
Examples of ARBs include:
Valsartan (Diovan)
Losartan (Cozaar)
Irbesartan (Avapro)
Olmesartan (Benicar)
Candesartan (Atacand)
It’s not uncommon to see ACE inhibitors and ARBs talked about together. However, there are some differences between them, including possible side effects.
No. ACE inhibitors and ARBs have a boxed warning (the FDA’s strictest warning) against their use during pregnancy. That’s because they’ve been shown to cause harm to the growing fetus.
As described earlier, ACE inhibitors and ARBs interfere with a specific pathway in your body to lower your blood pressure. But these actions can also interfere with how a fetus’ kidneys develop and work. This is especially the case during the second and third trimesters.
The amount of amniotic fluid around the fetus can also be decreased by ACE inhibitors and ARBs. This can be fatal or result in birth defects.
For these reasons, it’s highly recommended to avoid ACE inhibitors and ARBs while pregnant.
It’s typically recommended to stop taking an ACE inhibitor or ARB as soon as possible after finding out you're pregnant. But you should only do this under your healthcare provider’s supervision. Don’t abruptly stop taking your medication on your own.
Important steps in a growing fetus’ development happen during the second and third trimesters. Taking ACE inhibitors and ARBs during this time has been shown to be especially harmful. But studies suggest that using them during the first trimester might be risky, too.
So if you find out you’re pregnant, or if you’re trying to become pregnant, tell your healthcare provider right away. They’ll help you safely switch to a different treatment.
There are many different medications available to treat high blood pressure. Most of them don’t have enough evidence to know for sure if they’re safe to take during pregnancy. However, a handful are considered generally safe to take:
Methyldopa is commonly used to treat high blood pressure in pregnant women that works by relaxing blood vessels. It can cause some temporary side effects, such as sleepiness and dizziness. Methyldopa is usually taken 2 to 3 times a day.
Labetalol helps lower your blood pressure by slowing down your heart and relaxing blood vessels. It’s usually taken twice a day.
Nifedipine (Procardia) works by relaxing your blood vessels. It’s available as an extended-release version that’s only taken once a day.
Hydrochlorothiazide is a diuretic (water pill) that lowers blood pressure by removing extra water through your kidneys. It’s usually taken once a day.
Your healthcare provider will work with you to find a medication that meets your specific needs.
It’s important to make sure that any medications you’re taking during pregnancy won’t cause harm to the fetus. ACE inhibitors and ARBs are two medication classes that aren’t safe to take while pregnant since they can harm a growing fetus. But there are safer alternatives available.
If you’re taking one of these medications while pregnant or trying to become pregnant, contact your healthcare provider. They’ll help you safely switch to a different treatment. Don’t stop taking your medication on your own.
American College of Obstetricians and Gynecologists. (2021). How your fetus grows during pregnancy.
Buawangpong, N., et al. (2020). Adverse pregnancy outcomes associated with first-trimester exposure to angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers: A systematic review and meta-analysis. Pharmacology Research & Perspectives.
Croke, L. (2019). Managing chronic hypertension in pregnant women: ACOG releases updated practice bulletin. American Family Physician.
Garovic, V. D., et al. (2021). Hypertension in pregnancy: Diagnosis, blood pressure goals, and pharmacotherapy: A scientific statement from the American Heart Association. Hypertension.
Organization of Teratology Information Specialists (OTIS). (2022). Ace inhibitors. Mother To Baby | Fact Sheets.
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