Refractory hypokalemic metabolic alkalosis in pregnancy: Interplay of hyperemesis gravidarum and primary hyperparathyroidism

We report the case of a 32-year-old pregnant woman who presented at 9 weeks of gestation with severe hyperemesis gravidarum (HG) and metabolic disturbances. Biochemical testing revealed hypercalcemia with an inappropriately elevated parathyroid hormone (PTH) level. Subsequent imaging identified a parathyroid adenoma. This case highlights primary hyperparathyroidism as a rare but important differential diagnosis in refractory HG and underscores the diagnostic challenges of interpreting calcium and PTH values during pregnancy.