What are the risks?

The risks depend on the type of heart condition and how serious it is. Some examples are:

• Heart rhythm issues. These also are called arrythmia. Arrythmia can make the heart feel like it beats too fast, too slow or with an unusual rhythm. Tell your health care team if you have any of these symptoms. Heart rhythm issues can lead to blood clots. And blood clots raise the risk of other heart problems and stroke.

• Heart valve issues. The heart has four valves that keep blood flowing in the correct direction. Scarring or defects of the heart or its valves can raise the risk of complications during pregnancy. So can having an artificial heart valve. If your valves don't work right, you might have trouble tolerating the increased blood flow that happens during pregnancy.

  Valve problems or artificial valves carry another risk. They can make you more likely to get an infection of the lining of the heart and heart valves. This is called endocarditis. Without treatment, it can be life-threatening.

  Artificial heart valves that are made of strong, long-lasting materials are called mechanical valves. Mechanical valves pose serious risks during pregnancy. If you have a mechanical valve, blood-thinner medicines need to be adjusted by your health care team. And the risk of life-threatening blood clots of the heart valves goes up. Taking blood thinners can put the baby at risk too.

• Congestive heart failure. With heart failure, the heart doesn't pump blood as well as it should. As blood volume and stress on the heart rise during pregnancy, congestive heart failure can become worse.
• Congenital heart defect. If you were born with a heart problem, your baby has a greater risk of getting some type of heart defect too. You also might be at risk for heart problems during pregnancy and of premature birth.