ODP115 Primary Hyperparathyroidism in Pregnancy

INTRODUCTION: Primary hyperparathyroidism (HPT) is characterized by an overproduction of parathyroid hormone (PTH) by a parathyroid adenoma, parathyroid hyperplasia, or parathyroid carcinoma classically causing hypercalcemia. Incidence of this pathology during pregnancy is very low (1%), as the great majority of cases are diagnosed in adults >45 years old. When present,it can be associated with detrimental maternal and fetal outcomes. Complications may include maternal nephrolithiasis, hyperemesis, and pancreatitis, along with miscarriage, fetal demise, low birth weight, neonatal hypocalcemia, and tetany. Considering the incidence of HPT in pregnancy is uncommon, there is limited data regarding diagnostic and treatment options for these patients. CLINICAL CASE: This is the case of a 28-year-old pregnant female at 12 weeks gestational age (WGA) who had a history of Type 1 Diabetes Mellitus. She was evaluated regarding metabolic control during pregnancy, however, was incidentally found with hypercalcemia. She denied any history of fractures, abdominal discomfort, bone pains or nephrolithiasis; she also had no pertinent family history associated with hypercalcemia. Laboratories showed a calcium level of 14.9 md/dL (nl, 8.6-10.2) with a phosphorus level of 1.9 mg/dL (nl, 2.5-4.5), which raised the suspicion of HPT. Further workup demonstrated high parathyroid hormone (PTH) 245 pg/mL (nl, 18.4-80.1), vitamin D-25-OH 24.7 ng/mL (nl, 30-100) and 24hr urine calcium collection of 402.5 mg/24hr (nl, 100-300); the latter excluding the possibility of familial hypocalciuric hypercalcemia. Patient was managed conservatively with IV hydration resulting in mild improvement of calcium to 12.4 mg/dL. Thyroid/Neck ultrasound revealed a thyroid gland with normal homogeneous texture and no distinct focal vascularized structure to suggest parathyroid origin. Other diagnostic imaging for localization of parathyroid disease with technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy or single-photon emission Computed Tomography are not recommended in pregnancy due to insufficient safety data and radiation risk. After discussion with a multidisciplinary team including endocrine surgeons, endocrinologists, and obstetricians, an exploratory neck surgery for possible parathyroidectomy was recommended. She underwent surgery at 13 WGA where a left superior adenoma was identified and completely removed without complications. Intraoperative PTH levels revealed a pre-excision PTH of 342 pg/mL (18.4-80.1), post-excision PTH at 5 minutes of 76 pg/mL, and at 10 minutes of 50 ng/mL, suggestive of successful surgical removal. Pathology report was consistent with left superior parathyroid adenoma. Both calcium and phosphorus levels normalized post-surgery [Ca 9.6 mg/dL (nl, 8.6-10.2) and 2.7 mg/dL (2.5-4.5)]. CONCLUSION: This is an unusual case of a patient with asymptomatic severe hypercalcemia associated to HPT diagnosed during pregnancy. In this patient conservative medical treatment proved to be unsuccessful. Parathyroidectomy early on the 2 nd trimester was advantageous to avoid both maternal and fetal complications during pregnancy. Presentation: No date and time listed