Pulmonary arterial hypertension (PAH) during pregnancy and the postpartum period is associated with high maternal morbidity and mortality and requires close multidisciplinary management in expert centers. In this setting, non-specific symptoms such as hypotension, asthenia, anorexia, nausea, vomiting or weight loss may be initially attributed to progression of pulmonary vascular disease, right ventricular dysfunction, vasodilator-related adverse effects, excessive diuretic treatment or postoperative complications. We report the case of a patient with severe idiopathic PAH in whom persistent postpartum clinical deterioration after obstetric hemorrhage led to the diagnosis of hypopituitarism compatible with Sheehan syndrome.

A 29-year-old woman had severe idiopathic PAH confirmed by right heart catheterisation, with mean pulmonary arterial pressure 72mmHg, pulmonary arterial wedge pressure 13mmHg, pulmonary vascular resistance 25.6 Wood units and cardiac index 2.3L/min/m2. Given the initial high-risk profile, combination therapy including intravenous epoprostenol was started, followed by clinical stabilisation. One year later, she became pregnant. Current guidelines advise against pregnancy in women with PAH because of the substantial maternal and fetal risk, a recommendation particularly relevant in severe disease requiring advanced therapy [1]. She presented during pregnancy after a period of irregular follow-up. Despite detailed counselling regarding the very high maternal and fetal risks and a recommendation for termination, she chose to continue the pregnancy. Pulmonary vasodilator therapy was adjusted, maintaining systemic prostacyclin and phosphodiesterase-5 inhibitor treatment under close multidisciplinary follow-up. At 38 weeks, planned caesarean section was performed in a cardiac surgery operating room, with extracorporeal membrane oxygenation support available but not required, and subtotal hysterectomy was carried out. During the immediate postpartum period, she developed tachycardia and increased vasopressor requirements. Haemoglobin fell from 12.1g/dL at delivery to 8.2g/dL the following day. Computed tomography showed a heterogeneous pelvic haematoma in the surgical bed measuring 93mm×73mm×82mm, without active arterial or venous bleeding, associated with moderate haemoperitoneum. Exploratory laparotomy found haematic tissue without active bleeding; bilateral hypogastric artery ligation was performed and two packed red blood cell units were transfused. The patient subsequently achieved full haemodynamic and clinical recovery and was discharged home in a stable condition.

During postpartum follow-up, she reported dizziness, a tendency to hypotension, asthenia, reduced appetite, 12-kg weight loss, headache, nausea and vomiting. These symptoms persisted despite adjustment of prostacyclin and diuretic therapy. Blood tests showed hemoglobin of 10.4g/dL, hyponatremia of 127mEq/L and marked hypoglycemia of 37mg/dL. Cranial computed tomography was normal, and thoracoabdominopelvic imaging showed no relevant findings.

Given the persistence of constitutional symptoms and the history of severe obstetric hemorrhagic complication, the differential diagnosis was broadened to include endocrine causes. Hormonal assessment showed TSH <0.01mU/L, free thyroxine 0.88ng/dL, free triiodothyronine 2.41pg/mL, cortisol <1μg/dL and ACTH <5pg/mL. Additional pituitary testing showed FSH 1.1mU/mL, LH 0.4mU/mL, estradiol <24pg/mL, prolactin <0.8ng/mL and IGF-1 29ng/mL. These findings were consistent with panhypopituitarism. Sellar magnetic resonance imaging showed partial empty sella and slightly decreased pituitary size, without necrotic-hemorrhagic lesions. Hydrocortisone and levothyroxine replacement led to clinical recovery (Table 1).

This case highlights that persistent postpartum deterioration in PAH should not be attributed automatically to the pulmonary vascular disease or its treatment. In severe PAH, haemodynamic management of obstetric haemorrhage is particularly challenging: systemic hypotension may compromise right ventricular coronary and organ perfusion, whereas excessive fluid loading may worsen right ventricular failure; careful volume replacement and timely vasopressor support may therefore be required [2]. Severe obstetric haemorrhage followed by hypotension, hyponatraemia, hypoglycaemia and constitutional symptoms should prompt consideration of Sheehan syndrome, even when pituitary necrosis is not clearly demonstrated on imaging. Its diagnosis is often delayed because these manifestations are non-specific and may be attributed to postpartum recovery, anaemia, the underlying cardiopulmonary disease or its treatment [3–5]. Maintaining a broad differential diagnosis is essential in high-risk PAH pregnancies, as early recognition of a treatable endocrine cause may substantially change management and outcome.