Caring for a Patient with Previously Un-Diagnosed Hyperparathyroidism at 35 Weeks Gestation

Background: Primary hyperparathyroidism is an endocrine disorder rarely diagnosed in pregnancy. Those cases reported are usually diagnosed in the first or second trimester of pregnancy with very few in the third trimester. If untreated, hyperparathyroidism has the potential for serious maternal and/or neonatal complications including but not limited to neonatal tetany and serious electrolyte imbalances.

Case: A 28 year old hispanic female , gravida 1 para 0 at 35 weeks gestation was admitted for management of elevated blood pressures to rule out pre-eclamspia. She denied any physical complaints of headache, nausea/vomiting, shortness of breath, palpitations, chest pain, abdominal pain, visual disturbabces, contractions or vaginal bleeding. Her medical history was significant for hypothyroidism which was treated with Synthroid. She denied any other significant medical issues.

Her physical exam was within normal limits, blood pressures remained WNL with one elevation of 143/74. Fetal ultrasound was normal, FHR tracings were Category I. Routine labs drawn included CBC - WNL, PIH panel - WNL and chem screen which revealed a serum calcium of 12.2 ng/dL. Additional labs were a 24 hour urine calcium of 370 mg/day, 24 hour urine protein of 567 mg/day. TSH and free T4 were WNL. The diagnosis of hypercalcemia was made. The patient had an ultrasound of the thyroid and an MRI of the neck resulting in diagnosis of hyperparathyroidism secondary to left lower pole ademoma.

Multiple consults including MFM, endocrine, ENT surgery and neonatology were done.  Options deiscussed with patient and partner included conservative management, surgical management and potential neonatal outcomes. Patient initally opted for conservative management which included treatment with Calcitonin which did not decrease calcium levels. Premature delivery of fetus was also discussed but was decided against. Patient opted for surgical removal of the adenoma. Serum PTH levels obtained 30 minutes post-op decreased from 175pg/mL pre-op to 35 mg/mL. The post operative calcium levels dropped to 8.0 mg/mL from 11.3 mg/mL.

The patient was discharged on post-op day #2. She returned at 39 weeks 1 day for elective primary C-Section for persistent breech presentation. Her serum calcium was 9.2 mg/mL, PTH was 23 mg/dl. The neonate serum calcium was 9.7 mg/dl and demonstrated no adverse symptomatology of the maternal hypercalcemia.The patient was discharged with her baby on post-op day 4.

Conclusion: Although hyperparathyroidism is uncommon during pregnancy, it has the potential for serious negative outcomes. With surgical treatment, outcomes are much improved.

Keywords: hypercalcemia, hyperparathyroidism, pregnancy