If a patient with pulmonary arterial hypertension (PAH) decides to terminate her pregnancy, will her maternal mortality risk decrease and if so, by how much compared to continuing the pregnancy?

Maternal Mortality Risk Reduction with Pregnancy Termination in PAH

For a patient with pulmonary arterial hypertension (PAH), termination of pregnancy significantly reduces maternal mortality risk compared to continuing pregnancy, with first trimester termination offering the lowest risk (maternal mortality decreases from 30-50% with continued pregnancy to a substantially lower risk with early termination).

Risk Assessment of PAH in Pregnancy

Pregnancy in women with PAH carries an extremely high risk of maternal mortality:

• Historical mortality rates: 30-50% in older studies 1
• More recent mortality rates: 17-33% in contemporary series 1
• Mortality primarily occurs in the last trimester and first months postpartum 1

The pathophysiology behind this elevated risk includes:

• Decreased systemic vascular resistance during pregnancy
• Right ventricular overload
• Volume and hormonal fluctuations
• Risk of pulmonary hypertensive crises
• Pulmonary thrombosis
• Refractory right heart failure 1

Timing of Termination and Associated Risks

The risk profile varies significantly based on when termination occurs:

First Trimester Termination

• Lowest risk option for maternal mortality 1
• Recommended as the earliest possible intervention after diagnosis 1
• Should be performed in a tertiary center with PAH expertise 1, 2

Later Termination (Second/Third Trimester)

• Carries higher risk than first trimester termination 1
• Still likely lower risk than continuing pregnancy to term 1
• Class IIb recommendation: "Pregnancy termination in the last 2 trimesters of pregnancy poses a high risk to the mother. It may be reasonable, however, after the risks of termination are balanced against the risks of continuation of the pregnancy." 1

Continuing Pregnancy

• Highest risk scenario (30-50% mortality in older series) 1
• Even with modern management, mortality remains 17-33% 1
• Risk persists through delivery and postpartum period
• Class III recommendation: "Pregnancy in women with CHD-PAH, especially those with Eisenmenger physiology, is not recommended and should be absolutely avoided in view of the high risk of maternal mortality." 1

Management Recommendations if Termination is Chosen

If the patient chooses termination:

1. Perform at a specialized center with expertise in PAH management 1, 2
2. Multidisciplinary approach involving:
   • PAH specialists
   • High-risk obstetrics
   • Cardiac anesthesiology 1, 2
3. Careful hemodynamic monitoring during the procedure 1, 2
4. Avoid general anesthesia if possible (risk factor for mortality) 1
5. Continue PAH-specific therapies throughout the perioperative period 2

Future Pregnancy Prevention

After termination, focus should shift to preventing future pregnancies:

• Contraception counseling is essential 1
• Avoid estrogen-containing contraceptives due to VTE risk 1
• Consider surgical sterilization as a definitive option 1
• Dual mechanical barrier contraception recommended for patients on ERTAs (bosentan, ambrisentan, macitentan) 1

Conclusion

The evidence strongly supports pregnancy termination as a life-saving intervention for women with PAH who become pregnant. The risk reduction is substantial, with maternal mortality decreasing from 30-50% with continued pregnancy to a much lower risk with termination, particularly when performed in the first trimester at a center with PAH expertise.