Pregnancy and Pre-existing Heart Disease

What is pre-existing heart disease in pregnancy?

Pre-existing heart disease is a heart problem that you had before you got pregnant. This usually means a heart condition that you were born with (congenital). These can include heart problems that may have been fixed. It can also include heart valve issues.  

Common heart issues that may be affected by pregnancy include:

  • Mitral stenosis
  • Atrial septal defect
  • Ventricular septal defect
  • Aortic stenosis
  • Mitral valve prolapse

What causes pre-existing heart disease in pregnancy?

Most heart problems you’re born with happen by chance. No one knows what causes them. A heart valve problem may come on after an infection or other health condition. Rheumatic fever caused by strep throat is a common source of infection that affects heart valves.

Even if your heart disease doesn’t cause symptoms or hasn’t affected your life, it can cause issues during pregnancy. This is because of changes in your body that happen when you’re pregnant. Some women don't know they have pre-existing heart disease until the stresses of pregnancy reveal the problem.

Starting in your first trimester, your blood volume rises by about half. The extra fluid makes your heart work harder. Your heart responds by increasing its cardiac output. This is the amount of blood that goes through your circulatory system in 1 minute. Other systems in your body also respond. Your blood pressure decreases to allow the extra blood volume to flow. But some women develop high blood pressure instead. This can put more stress on your heart, especially if you have a pre-existing heart condition.

Changes in your heart and vascular system can also happen during labor and delivery. Large amounts of blood move from your uterus into your circulation, as your uterus contracts. This causes changes in your blood pressure, heart rate, and cardiac output. If you get an epidural or spinal anesthesia, this can also cause your blood pressure to decrease.  

After childbirth, your cardiac output increases and your heart rate slows down. You can have heavy blood loss with delivery. This can change your heart rate, blood pressure, and cardiac output.

What are the symptoms of pre-existing heart disease in pregnancy?

Most women with a pre-existing heart issue have been diagnosed and treated before pregnancy. Some women with minor heart problems may not know that they have a heart issue. These women, and women with repaired heart conditions, may develop symptoms during pregnancy.

The following are common symptoms of heart disease. Symptoms can occur a bit differently in each pregnancy. They may include:

  • Trouble breathing, especially at night or when you’re not active
  • Not being able to do normal activities, because of weakness or fatigue
  • Lightheadedness or fainting
  • Irregular heart rate (palpitations)
  • Blue skin coloring because of low levels of oxygen in your blood (cyanosis)

The symptoms of heart disease may look like symptoms of other health problems. Always see your healthcare provider for a diagnosis.

How is pre-existing heart disease diagnosed in pregnancy?

Heart problems are a possible complication in pregnancy. They happen in about 1 in 100 pregnancies.

Diagnosing a heart issue in pregnancy can be tricky. This is because some of the normal symptoms of pregnancy look like symptoms of heart disease.

Your healthcare provider will ask about your health history. He or she will also give you an exam. You may also need the following tests:

  • Electrocardiogram (ECG). This test notes the electrical activity of your heart. It also shows abnormal heart rhythms and looks for heart muscle damage.
  • Echocardiography. This test looks at the structure and function of your heart. It uses sound waves recorded on an electronic sensor. These show a moving picture of your heart and heart valves.
  • Right heart catheterization. This test involves putting a pressure monitor into the chambers of the heart. The monitor is put into a large vein in your neck or the groin and moved to your heart. Understanding how high or low the pressures in the heart are can help your healthcare team diagnose a problem. This can also help them come up with treatment choices that are best for you.

How is pre-existing heart disease treated in pregnancy?

Treatment will depend on your symptoms, pregnancy, and general health. It will also depend on how severe the condition is.

Your healthcare provider will look at the risk that your heart disease may have on your pregnancy. You may need to see a high-risk obstetrician. You may also need to see a heart doctor (cardiologist) who specializes in congenital heart disease or high-risk prenatal care.

You may need to see your healthcare provider more often. This is so he or she can watch you and your baby. You may also need medicine to help your heart work better.

Your healthcare team will decide the safest way for you to have your baby. You may give birth vaginally or you may need to have a cesarean section. During labor, you may need to have your heart monitored continuously.

What are the complications of pregnancy and pre-existing heart disease?

Normal changes in pregnancy may cause problems if you have heart disease. Your healthcare provider will watch you closely to make sure you and your baby stay healthy.

If you have a congenital heart defect, there’s a chance your baby will also have a heart issue. It may not be the same heart problem you have. You’ll likely need high-risk prenatal monitoring.

Living with pre-existing heart disease in pregnancy

Congenital heart disease is a life-long condition. Most of the time, your heart defect is fixed in childhood. Other times, you may not have symptoms for many years.

But pregnancy causes changes that can cause problems for women with heart disease. Before you get pregnant, you should consider preconception counseling. A specialist with experience in pregnancy and heart disease can help you. This can help you make choices about pregnancy. It can also help you learn how to maintain or improve your health.

Ask your healthcare team which heart medicines you take are safe to use during pregnancy. Some medicines can cause birth defects and should not be used. Don't stop taking your medicines without talking with your provider first. 

Online Medical Reviewer: Kang, Steven, MD

Online Medical Reviewer: Snyder, Mandy, APRN

Date Last Reviewed: 6/1/2018

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