How is pulmonary arterial hypertension (PAH) managed in pregnancy?

Management of Pulmonary Arterial Hypertension in Pregnancy

Pregnancy should be avoided in women with pulmonary arterial hypertension (PAH) due to high maternal mortality risk (17-50%), but if pregnancy occurs, patients should be managed at specialized PAH centers with multidisciplinary expertise. 1

Maternal and Fetal Risks

• Maternal death most commonly occurs in the last trimester of pregnancy and first months after delivery due to pulmonary hypertensive crises, pulmonary thrombosis, or refractory right heart failure 1
• Risk factors for maternal mortality include late hospitalization, severity of pulmonary hypertension, and general anesthesia 1
• Even patients with mild symptoms or minimal disability before pregnancy can experience significant deterioration during pregnancy due to decreased systemic vascular resistance and right ventricular overload 1
• Neonatal survival rates are reported to be 87-89%, though intrauterine growth restriction is common 1, 2

Management Approach

Pre-pregnancy Counseling

• PAH patients should be strongly advised to avoid pregnancy due to high mortality risk 1
• Effective contraception is essential - estrogen-containing contraceptives should be avoided due to increased VTE risk 1
• For patients on bosentan, ambrisentan, macitentan, or riociguat (Category X medications), dual mechanical barrier contraception is recommended 1

If Pregnancy Occurs

1. Initial Management:

   • Termination should be offered and discussed, particularly in high-risk cases 1
   • If termination is chosen, it should be performed at a tertiary center experienced in PAH management due to anesthesia risks 1
   • If pregnancy continues, refer immediately to a specialized PAH center with multidisciplinary expertise 1

2. Multidisciplinary Team:

   • Team should include pulmonary hypertension specialists, high-risk obstetrics, and cardiovascular anesthesiology 1, 3
   • Care should be coordinated at a center with all therapeutic options available 1, 4

3. Medical Therapy:

   • For patients already on PAH therapy before pregnancy:
     • Continue therapy but inform patients about potential teratogenic effects 1
     • Bosentan, ambrisentan, macitentan, and riociguat are contraindicated in pregnancy (Category X) 1
     • Sildenafil is often the preferred medication during pregnancy 2
   • IV prostacyclin or aerosolized iloprost may be used antenatally and peripartum to improve hemodynamics 1
   • Anticoagulation should be maintained during pregnancy if indicated outside of pregnancy 1
     • LMWH or UFH is preferred over oral anticoagulation 1
     • Individualize anticoagulation based on PAH etiology:
       • For PAH with congenital cardiac shunts: Consider in patients with pulmonary artery thrombosis or heart failure signs 1
       • For PAH with connective tissue disorders: Consider on individual basis 1
       • For PAH with portal hypertension: Not recommended if increased bleeding risk 1

4. Monitoring and Supportive Care:

   • Serial assessment of right heart function through echocardiography, BNP levels, and 6-minute walk tests 4, 5
   • Maintain adequate circulating volume while avoiding fluid overload 1
   • Prevent systemic hypotension, hypoxia, and acidosis which may precipitate heart failure 1
   • Provide supplemental oxygen for hypoxemia to maintain saturations >91% 1
   • Restrict physical activity and monitor oxygen saturation 1
   • For patients with Eisenmenger syndrome:
     • Prevent venous stasis (compression stockings, avoid supine position) 1
     • Consider prophylactic heparin for prolonged bed rest 1

5. Delivery Planning:

   • Plan delivery at a specialized center with PAH expertise 3, 4
   • Cesarean section with regional anesthesia is often preferred 4, 6
   • Avoid general anesthesia if possible due to increased risk 1
   • Hemodynamic monitoring is essential during delivery, though Swan-Ganz catheterization should be used cautiously due to risk of pulmonary artery rupture 1

6. Post-partum Care:

   • Highest risk period is the first month post-delivery 2
   • Continue close monitoring in intermediate care or ICU setting 3, 4
   • Be vigilant for clinical deterioration within the first week of delivery 2
   • Continue PAH-specific therapies 5

Recent Advances and Outcomes

• Recent case series from specialized centers report improved outcomes with multidisciplinary management 3, 4, 6
• Successful pregnancies have been reported when patients achieve low-risk status on PAH therapy before delivery 4, 5
• Despite improvements in care, maternal mortality remains high (reported 37.1% in one series), with most deaths occurring within the first month after delivery 2

Pitfalls to Avoid

• Delaying referral to a specialized PAH center 1
• Using general anesthesia instead of regional anesthesia 1
• Inadequate post-partum monitoring (highest risk period) 2
• Discontinuing PAH-specific therapies during pregnancy without appropriate alternatives 1
• Failure to maintain adequate oxygenation and prevent hypotension 1