For people with congenital heart defects, anticoagulants are taken to help thin out blood cells. Blood-thinning medicine slows down the blood clotting and prevents blood clots from forming on artificial valves. Valve obstruction and blood clots can travel to the brain and cause strokes.

Anticoagulants are usually given by mouth. In some cases, they’re given by vein or injection. For oral medications, anticoagulants generally include aspirin, clopidogrel, and warfarin. These medicines decrease clotting by interfering with platelets and blocking the body’s production of clotting substances. Aspirin is known to prevent more bleeding complications than clopidogrel or warfarin, however, it may not block clotting as much as the other two. It also can upset the stomach. Clopidogrel could cause bleeding for up to 7-10 days which may require you to avoid certain dental work and operations. Warfarin also increases bleeding and requires careful blood level monitoring by tests. It also requires you to limit some physical activities to reduce the chances of injury.

Intravenous (via the vein) medications works faster to thin blood. However, the effect wears off rapidly if treatment isn’t continued. Subcutaneous (via injection) medications include heparin. This is sometimes done during pregnancy or a certain long period of time, a much better option than oral or intravenous injections.

Anticoagulation and Pregnancy

For women who need anticoagulants during pregnancy, it is important to take special precautions. Warfarin can have significant risk on the fetus, especially in the first trimester. Please consult with your doctor, both your cardiologist and obstetrician, about which medication would best fit your health and your fetus’ health.