Hypercalcemic Crisis in Pregnancy With Acute Respiratory Distress Syndrome Requiring Extracorporeal Membrane Oxygenation.

Primary hyperparathyroidism (pHPT) during pregnancy is a rare but clinically significant condition associated with severe maternal and fetal complications. Diagnosis and management are challenging owing to symptoms overlapping with pregnancy-related conditions. A 28-year-old woman at 6 weeks of gestation presented with severe hypercalcemia (ionized calcium 2.80 mmol/L) (reference range, 1.15-1.29 mmol/L) leading to acute respiratory distress syndrome (ARDS), renal failure, and fetal demise. Despite initial management with hemodialysis and veno-venous extracorporeal membrane oxygenation (V-V ECMO), hypercalcemia and impaired respiratory status persisted until a parathyroid nodule was resected surgically. Postoperatively, calcium levels normalized, and the patient was successfully weaned off V-V ECMO; however, chronic kidney disease persisted. This case highlights the systemic effects of severe hypercalcemia in pregnancy, including ARDS and nephrocalcinosis. The case underscores the importance of a timely diagnosis and surgical intervention, as well as the need for a multidisciplinary approach to optimize outcomes in complex cases of pHPT during pregnancy. This report emphasizes the critical role of early recognition and management of pHPT during pregnancy to mitigate severe complications. Future research should focus on improving diagnostic strategies and refining treatment protocols for complex cases involving hypercalcemia-induced multiorgan dysfunction.