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Pregnancy: When you have a heart condition

Years ago, pregnancy was often considered too risky for women who had heart problems. Today, many women who have heart problems deliver healthy babies. Still, any heart condition requires special care during pregnancy. If you have a heart condition and are considering pregnancy, here's what you need to know.

How does pregnancy affect the heart?

Pregnancy stresses your heart and circulatory system. During pregnancy, your blood volume increases by 40 percent to 50 percent to nourish your growing baby. The amount of blood your heart pumps each minute increases by 30 percent to 50 percent. Your heart rate increases as well. All of these changes cause your heart to work harder.

Of course, labor and delivery add to your heart's workload, too. During labor — particularly when you push — you'll experience abrupt changes in blood flow and pressure. When your baby is born, decreased blood flow through the uterus also stresses your heart.

What are the risks?

The risks depend on the nature and severity of the underlying heart condition.

Minor abnormalities in heart rhythm — such as occasional extra atrial or ventricular beats — are common during pregnancy. They're not usually cause for concern.

If you have an artificial heart valve or your heart or valves are scarred or malformed, pregnancy may pose a risk of endocarditis — a potentially life-threatening infection of the lining of the heart and heart valves. Such scarring roughens the inner surface of the heart. This gives infecting organisms a place to congregate, multiply and potentially spread to other parts of the body. Some artificial heart valves also increase the risk of blood clots, particularly during pregnancy.

Some heart problems increase the risk of stillbirth, miscarriage and premature delivery. Congestive heart failure may become a concern as blood volume increases. Although rare, heart attacks also are possible.

If you have a congenital heart problem — a malformation that was present when you were born — your baby has a greater risk of developing one, too.

Do some heart conditions cause more complications than others do?

Yes. Certain heart conditions may pose life-threatening risks for mother or baby, including:

• High blood pressure in the arteries in the lungs (pulmonary hypertension)
• Severely obstructed blood flow between the left chambers of the heart (mitral valve stenosis)
• Severe narrowing of the aortic valve, which obstructs blood flow from the heart to the aorta (aortic stenosis)
• Marfan syndrome, a condition that weakens connective tissue in the heart, blood vessels or other body systems
• Eisenmenger's syndrome, a condition often characterized by a large hole in the heart and high blood pressure in the arteries in the lungs
• Cyanotic heart defects, a group of defects in which blood pumped to the body contains less oxygen than normal

These conditions may require major treatments, such as heart surgery, before you try to conceive. If the risks are too great, it may be best to avoid pregnancy.

What about medication?

Any medication you take during pregnancy can affect your baby. Often the benefits outweigh the risks, however. If you need medication to control your heart condition, your health care provider will prescribe the safest medication at the most appropriate dose. Take the medication exactly as prescribed. Don't stop taking the medication or adjust the dose on your own.

What should I do to prepare for pregnancy?

Before you try to conceive, schedule an appointment with the health care provider who'll be handling your pregnancy. Also meet with other members of your health care team, such as your family doctor or cardiologist. They'll evaluate how well you're managing your heart condition and consider any treatment changes you may need to make before pregnancy begins.

Certain medications commonly used to treat heart conditions aren't used during pregnancy. Depending on the circumstances, your health care provider may adjust the dosage or make a substitution.

What can I expect during prenatal visits?

During pregnancy, you'll see your health care provider often. Your weight and blood pressure will be checked at every visit, and you may need frequent blood and urine tests. Your health care provider may use various tests to evaluate your heart function as well:

• Echocardiogram, a test that uses sound waves to produce images of the heart
• Electrocardiogram, a test that records the heart's electrical activity

How can I make sure my baby is OK?

Your health care provider will closely monitor your baby's health throughout the pregnancy. Ultrasound exams may be used to track your baby's growth and development. Specialized ultrasounds may be used to detect any fetal heart abnormalities.

What can I do to prevent complications?

Taking good care of yourself is the best way to take care of your baby.

• Keep your prenatal appointments. Visit your health care provider regularly throughout your pregnancy.
• Take your medication as prescribed. Your health care provider will prescribe the safest medication at the most appropriate dose.
• Get plenty of rest. Take a daily nap, if you can, and avoid strenuous physical activities. Bed rest may be recommended in some cases.
• Monitor your weight. Gaining the right amount of weight supports your baby's growth and development, but gaining too much weight places additional stress on your heart.
• Prevent blood clots. When you're seated, keep your legs uncrossed. Tighten your leg muscles periodically or get up for short walks (with your health care provider's OK, if you're on bed rest). Support stockings may help, too. Sometimes medication to prevent blood clots is needed.
• Stay cool. Too much heat or humidity may dilate your blood vessels and increase demand on your heart.
• Reduce anxiety. Ask questions about your progress. Find out what to expect during labor and delivery. Knowing what's happening may help you feel more at ease.
• Know what's off-limits. Avoid smoking, alcohol and illicit drugs.

What signs or symptoms should I report to my health care provider?

Contact your health care provider if you have any signs or symptoms that concern you, particularly:

• Difficulty breathing
• Increased swelling
• Rapid weight gain
• Heart palpitations, rapid heart rate or irregular pulse
• Dizziness
• Chest pain
• Unusual fatigue or weakness

What about labor and delivery?

Your health care provider may recommend delivering your baby at a medical center that specializes in high-risk pregnancies and offers a neonatal intensive care unit.

During labor, you may need monitoring with specialized equipment. For example, a catheter may be inserted into a vein or artery to provide detailed information about your heart function. An echocardiogram may give your health care provider additional information about your heart.

To ease stress on your circulation, your health care provider may recommend epidural anesthesia for pain relief. If you deliver vaginally, your health care provider may limit the amount of time you push. Sometimes it's best to deliver the baby with the help of forceps or a vacuum extractor. If you're at risk of endocarditis, you may need antibiotic treatment just before and after delivery.

If the stress of labor could be dangerous for you or your baby, your health care provider may recommend a C-section.

Will I be able to breast-feed my baby?

Breast-feeding is encouraged for most women who have heart conditions, even those who take medication. Discuss any treatment adjustments you'll need to make with your health care provider ahead of time. Sometimes an alternate medication is recommended. In a few cases, breast-feeding may be limited to decrease demand on your heart.