Understanding Congenital Heart Disease & Pregnancy
Congenital heart disease (CHD) is the most common heart condition for women of child-bearing age. Caused by structural issues of the heart present at birth, the severity of congenital heart disease in women ranges from simple, which affects 50% of those with the condition to moderate (35%) and complex (15%).
We sat down with Scott M. Pilgrim, M.D., the medical director of the Adult Congenital Heart Disease Program at Cook Children’s Medical Center and physician on the medical staff at Texas Health Fort Worth, to share his advice and insights about the disease as it relates to pregnancy.
Dr. Pilgrim, should a woman with CHD consider pregnancy? And if so, what are the risks?
There’s really no simple answer, as the individual risks for pregnancy vary for each woman. Understanding one’s risk is directly tied to the severity of her heart disease, previous interventions, potential associated co-morbidities – or additional illnesses – and current status. The latter might include residual valvular and/or shunt lesions, rhythm disturbances, pulmonary hypertension and ventricular function.
Let’s compare the situation in a woman with CHD and a woman who doesn’t have it. First, it’s important to know that pregnancy in a woman with a structurally normal heart provides hemodynamic — or blood flow — challenges to the system, including volume loading, increased cardiac output, increased cardiac oxygen demand, relative anemia and increased heart rate. Adding those normal changes in pregnancy to a woman with CHD increases the challenges of managing the issue in pregnancy.
Again, I want to emphasize that the risk for pregnancy varies for each woman, but that said, and generally speaking, the risks of pregnancy include baseline or worsening ventricular dysfunction, arrhythmia – or rate and rhythm of the heart, congestive heart failure, risk of a blood clot in addition to the potential need for medical management of related side effects to the mother. In addition, there may be risks for the fetus, including premature birth, intrauterine growth restriction often related to the inability of the heart to increase output, and potential death of the fetus.
How will my prenatal care differ?
Prenatal care for patients with CHD should start before the pregnancy begins through pre-pregnancy counseling and genetic evaluation, when needed, to ensure a safe and risk-averse pregnancy. When I see a patient considering pregnancy, it’s important we address residual lesions, arrhythmias, ventricular dysfunction and other problems prior to pregnancy to provide the best opportunity for a successful pregnancy and delivery.
Once pregnancy is confirmed, I involve the congenital cardiologist as early as possible in order to monitor the pregnancy and cardiac status. This typically involves visits with the adult congenital heart disease program once per trimester (or more frequently if needed). Visits usually include a complete risk assessment, rhythm and function evaluation and advice about continued management of the pregnancy and intended delivery.
During prenatal care, we recommend the type of delivery to the patient, with normal vaginal delivery preferred when possible. A fetal echocardiogram is offered at approximately 20-24 weeks of gestation to assess potential cardiac structural anomalies and potential fetal arrhythmias. The Fetal Cardiology program at Cook Children’s Medical Center is especially suited for this purpose, providing in-depth imaging and consultative services to the patient, as required.
What are the chances my baby will have CHD?
The risk of being born with a congenital heart defect is usually about 0.8 – 1%, but women with congenital heart disease have a much higher chance of having babies with congenital heart defects. This risk is estimated to be somewhere between 4-10% based on current literature. Known genetic disorders such as 22q11 microdeletion and Noonan syndrome further increase the risk based on the heritability patterns of the genetic disorder and risks inherent with those diagnoses.
It should also be noted that men with congenital heart disease carry an increased risk of having children with congenital heart disease with the risk estimated to be slightly less at 3-5%. This risk should also be considered in pre-pregnancy counseling and factored into the decision to have a baby. A fetal echocardiogram should also be offered in this setting for a surveillance evaluation of the fetal cardiac anatomy.
What should I expect during labor and delivery?
Labor and delivery are both exciting and potentially stressful for the mother. Identifying and mitigating risks and providing a detailed plan is important to a successful delivery. Pain management considerations are taken into account with pre-labor anesthesia consult in conjunction with the cardiologist and obstetrician to determine the correct method of delivery and the need for monitoring. Telemetry monitoring is often used to evaluate the mother’s heart rhythm during and after labor.
Invasive monitoring is not generally necessary, but can be used in select circumstances. Post-delivery, there is a tendency to relax and become less concerned about cardiac complications. However, the week following delivery is a particularly vulnerable time for women with congenital heart disease due to large volume shifts and electrolyte derangements. Telemetry monitoring in a monitored unit or ICU setting is common for at least 24-48 hours postpartum. Outpatient follow-up with the cardiologist is requested within 2-4 weeks of discharge to re-assess function and re-establish baseline cardiac status.
Dr. Pilgrim, what is the bottom line for women with CDH who are considering pregnancy?
Generally, it is safe for most women with congenital heart disease to become pregnant and have a successful delivery. Consideration of pre-pregnancy risk factors and management of potential residual issues prior to pregnancy is of paramount importance. An individualized care plan created by a multidisciplinary group including congenital cardiology, maternal-fetal medicine specialists, anesthesia, fetal cardiology and cardiac/obstetric nursing provides the best chance for an event-free, safe pregnancy and delivery process.
The Adult Congenital Heart Disease Program at Cook Children’s Medical Center provides women of childbearing potential with important education regarding birth control options, pre-pregnancy counseling and risk assessment based on their individual heart disease. Women who are pregnant are followed in conjunction with the primary OB, high-risk perinatology, anesthesia, fetal cardiology and cardiology/OB nursing teams to monitor the pregnancy and coordinate a comprehensive delivery plan.