What is the management of mitral valve stenosis in pregnancy?

Management of Mitral Valve Stenosis in Pregnancy

Percutaneous mitral balloon commissurotomy is the intervention of choice for pregnant patients with severe mitral stenosis who remain symptomatic despite medical therapy. 1

Pre-Pregnancy Management

Evaluation and Risk Assessment

• All women with suspected mitral stenosis should undergo clinical evaluation and transthoracic echocardiography (TTE) before pregnancy 1
• Severe mitral stenosis is defined as mitral valve area ≤1.5 cm² 1
• Pre-pregnancy counseling by a cardiologist with expertise in managing valvular heart disease during pregnancy is essential for all women with severe mitral stenosis 1

Pre-Pregnancy Interventions

• Valve intervention is recommended before pregnancy for symptomatic patients with severe mitral stenosis (mitral valve area ≤1.5 cm², stage D) 1
• Percutaneous mitral balloon commissurotomy (PMBC) is recommended before pregnancy for asymptomatic patients with severe mitral stenosis who have valve morphology favorable for the procedure 1
• Pregnancy should be discouraged in women with severe mitral stenosis until appropriate intervention is performed 1

Management During Pregnancy

Medical Management

• Beta blockers are reasonable for rate control in pregnant patients with mitral stenosis if tolerated 1
• Diuretics may be used for symptomatic relief of pulmonary congestion 2, 3
• ACE inhibitors and ARBs are contraindicated during pregnancy 1
• Pregnant patients with severe mitral stenosis should be monitored in a tertiary care center with a dedicated Heart Valve Team 1

Interventional Management

• Percutaneous mitral balloon commissurotomy is reasonable for pregnant patients with severe mitral stenosis (mitral valve area ≤1.5 cm²) who remain symptomatic with NYHA class III to IV heart failure symptoms despite medical therapy 1
• The procedure has been shown to significantly increase mitral valve area (typically doubling it) and decrease left atrial pressure and mitral valve gradient 2, 4
• PMBC during pregnancy has demonstrated favorable outcomes with low maternal and fetal complications 2, 4
• For pregnant patients with severe mitral stenosis and valve morphology not favorable for PMBC, valve intervention is reasonable only if there are refractory NYHA class IV heart failure symptoms 1
• Valve operations should not be performed in pregnant patients with mitral stenosis in the absence of severe heart failure symptoms 1

Delivery Planning

• Vaginal delivery under epidural anesthesia is generally well-tolerated and low-risk unless obstetrically contraindicated 3
• Careful hemodynamic monitoring is essential during labor and delivery 3
• Heart rate control and careful fluid management are crucial during the peripartum period 1

Long-Term Outcomes

• Studies have shown favorable long-term outcomes after PMBC in pregnant women with severe mitral stenosis 4
• Event-free survival rates of approximately 54% have been reported at mean follow-up of 44 months 4
• Children born to mothers who underwent PMBC during pregnancy have shown normal growth and development 4

Important Considerations and Pitfalls

• Cardiac decompensation typically occurs late in pregnancy as hemodynamic burden increases, and after delivery due to autotransfusion and aorto-caval decompression 3
• The physiologic increase in heart rate and blood volume during pregnancy increases the mitral valve pressure gradient, which can precipitate heart failure in previously asymptomatic patients 2, 3
• Surgery under cardiopulmonary bypass carries a fetal mortality rate of 15-30% and should be restricted to life-threatening conditions 1
• When PMBC is performed during pregnancy, radiation exposure to the fetus should be minimized by abdominal and pelvic shielding 5
• Transesophageal echocardiography guidance during PMBC can help reduce fluoroscopy time 5