How is rheumatic heart disease managed in pregnancy?

Management of Rheumatic Heart Disease in Pregnancy

Women with rheumatic heart disease in pregnancy require multidisciplinary team management at specialized centers, with the primary goals being preconception risk stratification, optimization of cardiac status before conception, and vigilant monitoring throughout pregnancy and the postpartum period to prevent heart failure and maternal mortality. 1, 2

Preconception Counseling and Risk Assessment

• All women with rheumatic heart disease should undergo cardiac risk assessment before conception, as entering pregnancy with quiescent disease significantly improves maternal and fetal outcomes 1, 2
• Echocardiography must be performed to assess valve severity, particularly mitral stenosis severity (valve area) and degree of pulmonary hypertension 1, 2, 3
• Women with severe mitral stenosis (valve area <1.5 cm²), severe pulmonary hypertension (≥80 mmHg), or NYHA class III-IV should be counseled about high maternal mortality risk (up to 50% in severe cases) 4, 3, 5
• Pregnancy may be contraindicated in women with severe pulmonary hypertension (mortality 17-33%), severe symptomatic mitral or aortic stenosis, or NYHA class III-IV status 1, 2, 6

Multidisciplinary Team Approach

• High-risk patients must be managed by an interdisciplinary cardio-obstetrics team including cardiologists, maternal-fetal medicine specialists, obstetric anesthesiologists, and neonatologists at specialized centers 1, 2, 6
• Shared care should be organized with local hospitals for lower-risk patients, with clear protocols for escalation to tertiary centers 1

Hemodynamic Considerations

• Pregnancy increases plasma volume by 40% and cardiac output by 30-50%, with peak changes at 24-32 weeks gestation, placing maximum stress on stenotic valves 1
• Mitral stenosis is particularly poorly tolerated because increased cardiac output across the stenosed valve causes sharp increases in transvalvular gradient and left atrial pressure, precipitating pulmonary edema 1, 6
• The decrease in systemic vascular resistance partially compensates for regurgitant lesions, making them generally better tolerated than stenotic lesions 1

Medical Management During Pregnancy

For Mitral Stenosis:

• Beta-blockers are the cornerstone of medical therapy for mitral stenosis, controlling heart rate and allowing adequate diastolic filling time 6, 3
• Diuretics should be used cautiously for pulmonary congestion, avoiding excessive volume depletion that could compromise uteroplacental perfusion 1, 6
• Digoxin may be added for rate control, particularly if atrial fibrillation develops 6
• ACE inhibitors and angiotensin receptor blockers are absolutely contraindicated throughout pregnancy due to fetal renal toxicity and teratogenicity 1, 2

For Regurgitant Lesions:

• Diuretics are the primary therapy for heart failure symptoms in mitral or aortic regurgitation 1
• Nitrates and dihydropyridine calcium channel blockers (e.g., nifedipine) can be used as vasodilators since hydralazine is no longer recommended in early pregnancy 1
• Most women with regurgitant lesions tolerate pregnancy well unless regurgitation is severe or acute 1

Anticoagulation Management:

• Women with mechanical valves require therapeutic anticoagulation throughout pregnancy, creating significant management challenges 1
• Warfarin causes fetal embryopathy (particularly between 6-12 weeks) and should be avoided in the first trimester if possible, though it remains the most effective anticoagulant for mechanical valves 1, 4
• Low molecular weight heparin or unfractionated heparin should be substituted during the first trimester and near delivery 1
• Women with atrial fibrillation or prior thromboembolism require anticoagulation, with the regimen individualized based on valve type and risk factors 6

Monitoring During Pregnancy

• Clinical assessment should occur at least monthly in the first and second trimesters, then every 1-2 weeks in the third trimester for women with significant valve disease 6, 3
• Serial echocardiography should be performed each trimester to assess valve gradients, ventricular function, and pulmonary pressures 2, 6
• Women with severe mitral stenosis or NYHA class III-IV require more frequent monitoring, potentially including hospitalization in the third trimester 6, 3
• Fetal growth should be monitored with serial ultrasounds, as intrauterine growth restriction occurs more frequently with severe maternal disease 7, 5

Interventional Procedures During Pregnancy

• Percutaneous balloon mitral valvuloplasty (BMV) should be performed during pregnancy when indicated for severe symptomatic mitral stenosis unresponsive to medical therapy 6, 7, 3
• BMV is ideally performed after 20 weeks gestation to minimize fetal radiation exposure, using abdominal and pelvic shielding 6, 7
• The procedure is technically feasible and safe during pregnancy, with success rates similar to non-pregnant patients 7, 3
• Cardiac surgery during pregnancy carries high fetal mortality risk (up to 30%) and should be reserved only for life-threatening maternal conditions refractory to all other measures 1, 4

Labor and Delivery Management

Mode of Delivery:

• Vaginal delivery is preferred for most women with rheumatic heart disease, including those with compensated mitral stenosis 2, 6, 3
• Cesarean section should be reserved for obstetric indications or for women with severe decompensated heart failure, severe aortic stenosis, or acute cardiac deterioration 2, 6
• Spontaneous onset of labor is preferred; if induction is necessary, oxytocin with artificial rupture of membranes is appropriate 2

Intrapartum Management:

• Epidural analgesia is strongly preferred as it provides pain control, reduces catecholamine surge, and stabilizes cardiac output 2, 6
• Continuous maternal cardiac monitoring (ECG, pulse oximetry) and fetal heart rate monitoring are essential 2, 6
• Position the patient in left lateral decubitus or semi-recumbent position to optimize venous return and avoid aortocaval compression 2, 8
• Avoid fluid overload during intravenous infusions, as the autotransfusion from uterine contraction significantly increases preload 2, 6
• Shorten the second stage of labor with assisted delivery (forceps or vacuum) to minimize maternal Valsalva efforts 6
• For the third stage, use a single intramuscular dose of oxytocin; ergometrine is absolutely contraindicated due to its vasoconstrictive effects and risk of precipitating pulmonary edema 2, 6

Postpartum Management

• The postpartum period represents a second critical high-risk window, with significant hemodynamic shifts occurring in the first 24-48 hours after delivery 2, 6, 3
• Autotransfusion from the contracted uterus and lower extremities can increase preload by 500-1000 mL, potentially precipitating acute pulmonary edema 2, 6
• A single intravenous dose of furosemide (20-40 mg) is commonly administered immediately after delivery to prevent fluid overload 2
• Continuous monitoring in a high-dependency or intensive care setting for at least 24-48 hours postpartum is essential for women with moderate-severe disease 2, 6
• Heart failure and arrhythmias are the most frequent postpartum complications, with maternal deaths occurring up to 6 months postpartum 6, 4, 3
• Anticoagulation should be restarted when postpartum bleeding has stopped, in consultation with obstetric and anesthesia teams 2

High-Risk Indicators and Outcomes

Predictors of Poor Maternal Outcome:

• Prepregnancy NYHA class >II is the strongest independent predictor of maternal cardiac events during pregnancy 3
• Severe mitral stenosis (valve area <1.5 cm²) is associated with 48% rate of heart failure during pregnancy 3, 5
• Severe pulmonary hypertension (≥80 mmHg) carries extremely high risk of maternal mortality 1, 5
• Atrial fibrillation significantly increases risk, with 86% of these patients developing NYHA class III-IV symptoms 5

Fetal and Neonatal Outcomes:

• Women with NYHA class III-IV deliver at earlier gestational ages (average 34.6 weeks) with lower birth weights (average 2176 g) compared to NYHA class I-II 5
• Perinatal mortality ranges from 3-5% in women with severe disease 4, 5
• Fetal growth restriction occurs in approximately 6% of pregnancies complicated by severe maternal cardiac disease 5
• Preterm delivery (medically indicated) occurs in up to 28% of high-risk pregnancies 5

Critical Pitfalls to Avoid

• Do not miss the diagnosis: Rheumatic heart disease is now rare in Western countries except in immigrants, and shortness of breath may be wrongly attributed to normal pregnancy or asthma rather than mitral stenosis 1
• Do not delay referral: Many women in developing countries present for the first time during pregnancy when they deteriorate clinically, missing the opportunity for preconception optimization 6, 7
• Do not use mechanical valves in young women of childbearing age when tissue valves are feasible, due to the severe complications of warfarin embryopathy 4
• Do not underestimate postpartum risk: Three additional maternal deaths occurred within 6 months postpartum in one registry study, emphasizing the need for extended postpartum surveillance 3