Hypercalcemic Crisis in Pregnancy: A Rare Case of Primary Hyperparathyroidism Complicated by Wernicke's Encephalopathy and Multi-Organ Involvement

Primary hyperparathyroidism (PHPT) and Wernicke’s encephalopathy (WE) are rare but potentially life-threatening conditions in pregnancy, associated with significant maternal and fetal morbidity. Their coexistence is exceptionally uncommon and poses major diagnostic and therapeutic challenges, requiring a coordinated multidisciplinary approach. We report the case of a 37-year-old multigravida (gravida 5, para 4+0) at 23 weeks and 6 days of gestation who presented with acute epigastric pain, vomiting, and rapidly progressive altered mentation progressing to obtundation. Her history was notable for recurrent nephrolithiasis and suspected parathyroid disease. Investigations revealed severe hypercalcemia (peak 3.29 mmol/L), markedly elevated parathyroid hormone (124 pg/mL), acute pancreatitis, leukocytosis, and lobar pneumonia. Brain MRI demonstrated characteristic findings of WE. Abdominal ultrasound showed cholelithiasis and steatohepatitis, while obstetric ultrasound confirmed a viable fetus. She was admitted to the intensive care unit and treated with high-dose intravenous thiamine, broad-spectrum antibiotics, aggressive intravenous hydration, diuretics, calcitonin, hydrocortisone, and cinacalcet. Despite maximal medical therapy, hypercalcemia persisted. Following multidisciplinary consensus, parathyroidectomy was performed at 27 weeks’ gestation, confirming a left inferior parathyroid adenoma. Postoperatively, calcium levels normalized and neurological status improved. The patient was discharged in stable condition. The pregnancy progressed without further complications, and she subsequently delivered a healthy neonate with no reported perinatal complications. This case underscores the importance of early recognition and multidisciplinary management of PHPT complicated by WE in pregnancy. Timely surgical intervention can be lifesaving and result in favorable maternal and fetal outcomes when medical therapy fails. • Rare coexistence of primary hyperparathyroidism and Wernicke encephalopathy. • PHPT-induced vomiting likely triggered severe thiamine deficiency and WE. • Diagnosis confirmed by elevated PTH, calcium, and characteristic brain MRI. • Second-trimester parathyroidectomy resolved refractory hypercalcemia. • Multidisciplinary care ensured favorable maternal and fetal outcomes.