The American Heart Association (AHA) released a scientific statement for healthcare practitioners on the management of pregnancy in patients with congenital heart disease.
As a result of the many medical advancements made in congenital heart disease, more women who are born with congenital heart disease will reach reproductive age. Therefore, the AHA writing committee recommends that all healthcare professionals involved in a patient’s pregnancy be advised of the most up-to-date guidelines and information associated with the condition.
The World Health Organization categorizes patients into 4 pregnancy risk classes (I-IV), depending on their specific medical condition. (Note: patients in class I have no detectable increased risk for maternal mortality and either no or only mild increase in morbidity; therefore, they are not included in this document.) Patients in classes II and III may have small increases in maternal mortality or moderate increases in morbidity. Class IV patients may have an “extremely high risk” for maternal mortality or severe morbidity to the degree that pregnancy would be ill-advised. According to the AHA, the World Health Organization risk algorithm is considered the most reliable at determining maternal cardiovascular risk.
Preconception counseling is recommended for any patient with congenital heart disease. This initial diagnostic evaluation should include a detailed history of any current cardiovascular symptoms, as well as family history, medication review, arterial oxygen saturation, and baseline laboratory tests (eg, complete blood count, electrolytes, and thyroid and liver function), electrocardiogram, cardiopulmonary or exercise stress tests, comprehensive echocardiogram, and genetic counseling consideration. “If there is doubt about the presence or absence of pulmonary hypertension, cardiac catheterization should be performed,” the authors wrote.
With regard to genetic testing, both the AHA and the Canadian Cardiovascular Society have produced consensus statements clinicians can use as guidelines.
A patient’s medications should also be reviewed and monitored. Anticoagulants, endothelin receptor antagonists, and statins are listed as “category X” by the US Food and Drug Administration. This categorization denotes that studies of the agent have “demonstrated fetal abnormalities” and that “the risk of the use of the drug in pregnant women clearly outweighs any possible benefit.”
Within the first trimester, clinicians should review the patient’s cardiac history as well as conduct preconception diagnostic evaluations. New arrhythmias, murmurs, or clinical evidence of heart failure should be noted. At this point, the frequency of cardiology visits is largely individualized, based on risk and development of symptoms or complications.
The second trimester is often when the greatest magnitude of hemodynamic changes occur. The AHA recommends that “A clear and coordinated plan for labor, delivery, and postpartum care should be developed by the end of the second trimester and distributed to all members of the multidisciplinary team, including labor and delivery staff, in the event of a spontaneous or indicated preterm delivery.”
In the third trimester, normal symptoms of pregnancy (eg, edema, dyspnea on exertion) may worsen, so patients should be monitored closely. All delivery planning should be finalized.
The AHA also makes recommendations for specific cardiac conditions such as arrhythmia, mechanical heart valves, heart failure, pulmonary arterial hypertension, aortic stenosis, and left ventricular outflow tract obstruction, among others.
Of note, cardiac monitoring is recommended for women with a history of arrhythmias (before conception) or those who develop arrhythmias during pregnancy. Pacemaker function should be assessed before pregnancy. For women with mechanical valves, a transthoracic echocardiogram should be performed to determine valve function, and anticoagulation should be administered to prevent serious thromboembolic complications. Low-dose aspirin (75 to 100 mg/d) is also recommended during the second and third trimesters.
Pregnancy is strongly ill advised in women with severe systemic ventricular dysfunction (left ventricular ejection fraction <30%, New York Heart Association class III or IV). However, for those women who do become pregnant, frequent monitoring is essential, and follow-up should be done at a center with expertise in pregnancy and heart disease.
In women with pulmonary hypertension, management should be focused on the “optimization of [right ventricle] preload and systolic function and reduction in [pulmonary vascular resistance].” If the patient is followed up on an outpatient basis, counseling should focus on reduction of cardiac demands via lowering activity level, enhanced bed rest, and salt intake limitation, among other measures. These patients should be monitored more frequently, as deterioration may occur as early as the second trimester.
Patients with moderate or severe aortic stenosis should be regularly followed up by a multidisciplinary team, particularly for early symptoms of heart failure, angina, or syncope/presyncope. Echocardiography is recommended to monitor the severity of aortic stenosis and ventricular function. As with other cardiac conditions, a detailed labor and delivery plan should be created.
Vaginal delivery is generally preferred for patients with nonsevere aortic stenosis, but if a patient has symptomatic severe aortic stenosis, clinicians may consider caesarean delivery with endotracheal intubation and anesthesia. Patients with severe aortic stenosis also have increased risk for obstetric complications, including intrauterine growth retardation, preterm birth, and low birth weight.
Although many patients with congenital heart disease will not encounter these issues during pregnancy, the AHA notes that patients with complex disease may face an increased risk for complications, regardless of clinical stability at the time of conception.
Canobbio MM, Warnes CA, Aboulhosn J, et al; on behalf of the American Heart Association on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; Council on Cardiovascular Disease in the Young; Council on Functional Genomics and Translational Biology; and Council on Quality of Care and Outcomes Research. Management of pregnancy in patients with complex congenital heart disease. A scientific statement for healthcare professionals from the American Heart Association [Published online January 12, 2017]. Circulation. doi:10.1161/CIR.00000000000000458