Advances in medicine have led women with congenital heart disease to live longer and reach childbearing age. There are many specific recommendations based on the type of CVD a woman has. Women with CVD must have a primary doctor and a cardiovascular specialist. Ideally, these women should have preconception counseling to learn the risks associated with pregnancy and develop a care plan for pregnancy and delivery. Some medications should be avoided during pregnancy. These include warfarin, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), aldosterone antagonists, thiazide diuretics, and certain antiarrhythmics (e.g., amiodarone). The World Health Organization (WHO) categorizes patients into four pregnancy risk classes (I-IV), depending on their specific condition (Friel, 2022).
Women with category I CVD have no increased risk of maternal mortality or morbidity. These are women with (Friel, 2022; Suwanrath et al., 2018):
- Uncomplicated or mild:
- Patient ductus arteriosus
- Pulmonic stenosis
- Mitral valve prolapse
- Repaired atrial septal defect
- Repaired ventricular septal defect
- Repaired anomalous pulmonary venous drainage
- Repaired patent ductus arteriosus
- Atrial ectopic beats
- Ventricular ectopic beats
Women with category II CVD have a mild risk of maternal mortality and a moderate risk of morbidity. These are women with (Friel, 2022; Suwanrath et al., 2018):
- Unrepaired atrial septal defect
- Unrepaired ventricular defect
- Repaired tetralogy of Fallot
- Mild left ventricle compromise
- Repaired coarctation of the aorta
- Hypertrophic obstructive cardiomyopathy
- Marfan syndrome without aortic dilation
- Bicuspid aortic valve with aorta < 45 mm
Women with category III CVD have a substantially elevated risk of maternal mortality and a severely elevated risk of morbidity. These women need to be closely monitored by a cardiologist throughout pregnancy and after pregnancy. These are women with (Friel, 2022; Suwanrath et al., 2018):
- Mechanical valve
- Fontan circulation
- Unrepaired cyanotic heart defects
- Systemic right ventricle
- Marfan syndrome with aorta dilated to 40-45 mm
- Bicuspid aortic valve with aorta dilated to 45-50 mm
Category IV patients may have an extremely high risk for maternal mortality or severe morbidity, so pregnancy is not advised. Termination is recommended for these women; close monitoring is necessary if the woman chooses to continue the pregnancy. These are women with (Friel, 2022; Suwanrath et al., 2018):
- Pulmonary arterial hypertension (any class)
- Severe left ventricular compromise (ejection fraction < 30%)
- Prior postpartum cardiomyopathy
- Severe mitral stenosis
- Severe aortic stenosis
- Marfan syndrome with aortic dilatation > 45 mm
- Bicuspid aortic valve disease with aortic dilatation > 50 mm
These women may require activity restriction or bed rest after 20 weeks of gestation.
Women with category I and II CVDs can deliver at their local hospital with cardiovascular consultation. Maternal-fetal medicine should be available for women with category II CVD. Women with categories III and IV should deliver at a hospital with appropriate care, where cardiovascular team members can participate in caring for these women. Women with category IV CVD may require care from the obstetrician, maternal-fetal medicine provider, interventional cardiologist, cardiovascular surgeon, and mental health specialists.
Women should have baseline labs and cardiovascular tests during the first trimester. Medications should be altered as needed. A coordinated labor, delivery, and postpartum care plan should be developed by the end of the second trimester and reviewed with a multidisciplinary team, including labor and delivery staff and the anesthesiology department. In the third trimester, normal pregnancy symptoms may worsen and require close monitoring.
Some treatments may be required during pregnancy. Patients with cardiomyopathy may experience atrial fibrillation during pregnancy. Medications to control a safe heart rate in pregnancy may include beta-blockers, calcium channel blockers, or digoxin. Anticoagulation may also be required. Pregnant women may be given standard or low-molecular-weight heparin. The timing and dosage of these medications may be altered at the time of delivery. The American Heart Association (AHA) guidelines do not recommend endocarditis prophylaxis because the rate of bacteremia is low (Friel, 2022). Loop diuretics can be used to treat pulmonary edema. It is important to treat hypertension during pregnancy. Severely high blood pressure (> 160/110 mm Hg) persisting for 15 minutes requires prompt treatment (within 60 minutes).
The AHA recommends delivery methods for patients with specific cardiovascular conditions such as arrhythmias, mechanical heart valves, heart failure, pulmonary arterial hypertension, aortic stenosis, and left ventricular outflow tract obstruction. Women with stable CVD can usually try to have a vaginal delivery at 39 weeks of gestation, with cesarean delivery performed as needed for obstetric complications. Some patients with high-risk cardiovascular conditions may not tolerate the fluctuations in cardiac output or Valsalva efforts that occur during vaginal delivery. Regional anesthesia during labor may provide sufficient pain relief for many patients to render a vaginal delivery feasible. Some of these women may require operative vaginal assistance during the 2nd stage of labor, and some women will need a cesarean section (ACOG, 2019). Women with aortic stenosis should have it repaired before pregnancy. These patients should not receive epidural or spinal anesthesia if the repair has not occurred. Women with arrhythmias may require cardiac monitoring during labor, so ensuring that the labor and delivery unit can accommodate this is essential. It is also important to have a plan to manage anticoagulation medications. The most important part of caring for a woman with CVD is to have a plan for these women when they come to the hospital to deliver. The anesthesiologists should know their history and have a plan of action. Most of these women will benefit from an epidural, whether in labor or having a cesarean section.
If cardiac arrest occurs, although rare, resuscitation is similar to a non-pregnant person. However, early intubation is recommended due to increased oxygen needs, and the woman’s uterus should be displaced. Prompt delivery is also recommended (ACOG, 2019).