Treatment of pulmonary arterial hypertension in pregnancy

Purpose. The treatment of pulmonary arterial hypertension (PAH) in pregnancy is reviewed. Summary. PAH is a disease characterized by narrowing of the pulmonary arteries and increased vascular resistance. Women with PAH should avoid becoming pregnant, as the physiological, cardiovascular, and pulmonary changes that occur during pregnancy can exacerbate the condition. However, several viable treatment options are available to improve the outcomes in this patient population, including inhaled nitric oxide, calcium-channel blockers, targeted pulmonary vasodilators, and sildenafil. Epoprostenol, a naturally occurring prostaglandin and vasodilator, is a pregnancy category B drug. Reproductive studies in rats and rabbits have found no impaired fertility or fetal harm at 2.5-4.8 times the recommended human dosage of epoprostenol. Most of the published case reports describe initiating epoprostenol 2-4 ng/kg/min i.v. several weeks before or near the time of delivery. iloprost is a pregnancy category C drug but has demonstrated benefit in pregnant patients with PAH, with no congenital abnormalities and no postpartum maternal or infant mortality reported. Sildenafil causes vasodilation of the pulmonary vascular bed and vasodilation in the systemic circulation. Two case reports have described the successful treatment with sildenafil, a pregnancy category B drug, of pregnant patients with PAH. Patients with idiopathic PAH or chronic thromboembolic PAH should receive full-dose subcutaneous low-molecular-weight heparin therapy instead of warfarin for bleeding prophylaxis during pregnancy. Conclusion. Targeted pulmonary vasodilators are viable treatment options for pregnant patients with PAH. Early recognition and management of worsening symptoms are essential to improve outcomes for both the mother and infant.