BackgroundPulmonary arterial hypertension is a rare disease associated with high rates of mortality and can significantly complicate pregnancy posing health risks for the mother and child alike.Case summaryWe present the case of a 37-year-old female patient with World Health Organisation functional Class IV symptoms during the 34th week of her 3rd pregnancy. Initial echocardiography showed a significantly elevated estimated systolic pulmonary artery pressure of 86 mmHg + central vein pressure as well as signs of chronic pulmonary hypertension. After a successful emergent caesarean section, pulmonary hypertension was confirmed via right heart catheterization. After exclusion of secondary aetiologies of pulmonary hypertension, the diagnosis of Class 1 pulmonary artery hypertension was made. We initially treated the patient with the phosphodiesterase-5 inhibitor sildenafil (20 mg oral bid trice daily) and later extended the medication with the dual endothelin receptor antagonist Macicentan (10 mg daily). Since the patient remained symptomatic vasodilator testing was performed and showed a significant response to intravenous Epoprostenol. We initiated a high-dose calcium channel blocker (CCB) therapy with amlodipine (20 mg daily) which led to symptomatic relief, increased exercise capacity as well as reduction in mean pulmonary artery pressure and pulmonary vascular resistance as confirmed by another right heart catheterization after therapy initiation.DiscussionSince the presentation is usually non-specific, the diagnosis of pulmonary artery hypertension can be challenging and cause a delay in treatment initiation. Even though rare vasodilator testing and invasive haemodynamic measurements should be performed to identify patients with favourable long-term response to high-dose CCB.