DEAR MAYO CLINIC: I am 32 and have lived with a congenital heart issue since childhood. I am newly married and would like to have children, but I understand that a pregnancy might be high-risk for me. How does pregnancy affect the heart? And is there anything I can do to reduce my risk for complications if I do conceive?
ANSWER: Pregnancy results in many changes that can increase the workload of the heart. During pregnancy, your blood volume increases by 30% to 50% to nourish your growing baby. Your heart pumps more blood each minute, and your heart rate increases. Rapid changes occur during labor and delivery that affect the heart, as well, and further increase the workload. After delivery, it will take several weeks for your body to return to the prepregnancy state.
The increased workload during pregnancy and delivery can cause some complications. However, many women who have heart conditions deliver healthy babies. If you have a heart condition, you'll need special care during pregnancy to reduce the risk of complications to you and your baby.
Maternal cardiac disease complications occur in about 1% to 3% of all pregnancies. The risks depend on the nature and severity of your heart condition.
Because you were born with a congenital heart defect, your baby has a greater risk of developing some type of heart defect, too. You also might be at risk for heart problems occurring during pregnancy and/or premature birth, depending on your specific heart defect.
Depending upon your specific cardiac anomaly, a pregnancy can complicate other issues you may have, including:
Before you try to conceive, you may want to schedule an appointment with a maternal cardiologist who is experienced in managing heart disease during pregnancy. This would be a specialist who would work in conjunction with the health care professional who will handle your pregnancy.
A maternal cardiologist will evaluate your current heart condition, discuss the risk of pregnancy specific to you and your condition, and make recommendations for treatment changes prior to pregnancy.
Certain heart conditions should be treated before pregnancy to make the pregnancy lower risk. This can include heart surgery, for example, to treat a heart valve condition such as aortic stenosis. Pregnancy is high risk for women with high lung artery pressures, or pulmonary hypertension, or severely reduced heart function. In these cases, it is advisable to avoid pregnancy.
Also, since some medications can affect a baby in the womb, certain medications used to treat heart conditions aren't used during pregnancy. If you need medication to control your heart condition, the specialist can review and make any adjustments. Depending on the circumstances, your dose may need to be modified, or you may require an alternative medicine. It is important that throughout your pregnancy you take the medication exactly as prescribed. Don't stop taking the medication or adjust the dose on your own.
During pregnancy, you may be referred to a maternal fetal medicine specialist, which is an obstetrician who specializes in high-risk pregnancies. Depending on the circumstances, you also may be referred to a medical geneticist, a neonatologist and an obstetric anesthesiologist to help manage your pregnancy and delivery. Most women with heart conditions can and should deliver their baby vaginally. Cesarean delivery is reserved for obstetrical reasons and rare cardiac complications. — Dr. Sabrina Phillips, Cardiovascular Medicine, Mayo Clinic, Jacksonville, Florida