A Case of Hyperparathyroidism Treated With Cinacalcet During Pregnancy

ABSTRACT Objective: Hyperparathyroidism during pregnancy is associated with increased maternal and neonatal complications. Cinacalcet is a calcimimetic medication that is used in the treatment of hyperparathyroidism; its use in pregnancy is limited to a few case reports. Methods: Case report and literature review. Results: We are reporting on a 37-year-old patient who was admitted to the hospital with dyspnea at 24 weeks gestation. A routine blood test revealed hypercalcemia; corrected calcium level was 3.17 mmol/L, and parathyroid hormone was elevated at 168 pg/mL. The patient was asymptomatic. Following her last delivery 10 years previously, her newborn developed severe tetany and needed treatment with intravenous (IV) calcium. Neck ultrasound was normal. Due to obesity and history of recurrent deep venous thrombosis, neck exploration was not favored. Initial treatment included calcitonin and IV fluids. The aim was to keep her calcium level as normal as possible to avoid any fetal complications. She was started on cinacalcet 15 mg once per day, which was increased later to 15 mg twice daily. By 36 weeks gestation, corrected calcium levels were down to <2.60 mmol/L. The patient was scheduled to deliver via elective cesarean section at 38 weeks, but she presented at 37 weeks in labor pain and delivered via emergency cesarean section. Postdelivery, the neonate calcium levels remained normal. Conclusion: During pregnancy, parathyroid surgery is the recommended treatment. Cinacalcet could be one of the options in severe cases of hypercalcemia if surgery cannot be performed. Further studies are needed to examine the safety of cinacalcet in pregnancy. Abbreviations: IV = intravenous; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone