Skip to main content

Pregnancy and atrial fibrillation

Medically reviewed by Last updated on Sep 9, 2021.

If you have atrial fibrillation, a common heart rhythm disorder (arrhythmia), you might need to change how you manage the condition during your pregnancy. For instance, you might need to avoid certain medications while you are pregnant.

Atrial fibrillation increases your risk of developing blood clots in your heart. Pregnancy increases your risk of developing blood clots in your legs. Taking blood-thinning medications can help reduce your risk of blood clots, but certain blood thinners may not be safe to take during pregnancy.

If possible, discuss your condition and medications with your doctor before you become pregnant. Pregnancy can make atrial fibrillation worse. It's also possible to develop atrial fibrillation while you're pregnant. Talking openly with your doctor allows him or her to develop the safest treatment plan for you and your developing baby.

Blood-thinning medications to avoid during pregnancy

If you take the blood-thinner medication warfarin (Coumadin, Jantoven) to reduce the risk of blood clot formation in atrial fibrillation, your doctor might recommend switching to a different blood thinner during all or part of your pregnancy. Warfarin may be associated with pregnancy risks.

Other blood thinners taken by mouth to prevent blood clots in atrial fibrillation, including dabigatran (Pradaxa), rivaroxaban (Xarelto) and apixaban (Eliquis), are not recommended during your pregnancy. There aren't enough studies to determine their effects and safety during pregnancy.

Blood thinners used during pregnancy, labor and delivery

Studies show that heparin, another blood-thinning medication, is safe to take while you're pregnant. Some pregnant women with atrial fibrillation are prescribed injections of heparin to prevent blood clots.

Even when taking blood-thinning medications, you're still at risk of developing blood clots during pregnancy. Watch for signs or symptoms of blood clots, such as chest pain, shortness of breath, leg swelling or warnings of stroke, including changes in vision, trouble speaking and numbness in the face, arms or legs. Contact your doctor immediately if you notice unusual signs or symptoms.

Heparin and other blood-thinning medications do increase your risk of major bleeding. If you notice any bleeding, contact your doctor. Blood-thinning medications are usually stopped during labor and delivery, unless you're at very high risk of blood clots.

After delivery

You can usually start taking your blood-thinning medication again after your child is born. Your doctor will give you specific instructions. Some blood thinners might not be recommended if you're breast-feeding. Together, you and your doctor can determine which blood-thinning medication is safe for you and your baby.

© 1998-2019 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use.