7506 Rare Case of Hyperparathyroidism in Third Trimester Pregnancy Requiring Urgent Parathyroidectomy
Authors: Costris A Rothstein , Davydov E , Levy S 
Published: October 2024

Abstract
Disclosure: A. Rothstein Costris: None. E. Davydov: None. S. Levy: None.
Introduction: Primary hyperparathyroidism (PHPT) during pregnancy has risks to both the mother and her fetus. Complications include maternal pre-eclampsia, miscarriage, hyperemesis gravidarum, nephrolithiasis and pancreatitis. Fetal complications encompass hypocalcemia, tetany, intrauterine growth retardation and fetal demise. Though medical treatment is available, parathyroidectomy is the only definitive treatment. Traditionally, surgery is done in the second trimester of pregnancy. We report a case of a third trimester parathyroidectomy in a 29 yo female with PHPT. Case representation: A 29-year-old G1P0 woman at 28 weeks gestation presented with persistent nausea and vomiting, constipation, joint pain, and increased forgetfulness. She has moved to USA from Saudi Arabia and had not received prenatal care in the USA. She was found to have a PTH of 224 (15-65 pg/mL), Calcium of 13.5 (8.2-10.2 mg/dL), Ionized Calcium of 1.63 (1.00-1.35 mmol/L), and a corrected Calcium of 14.2 (8.7-10.1 mg/dL). Electrolyte abnormalities were also noticed, with a Potassium of 2.8 (3.5-5 mmol/L), Phosphorus of 1.7 (2.5-4.5 mg/dL) and Magnesium of 1.2 (1.8-2.3 mg/dL). Vit. D levels were found to be extremely low &lt;7 (20-40 ng/mL). Due to severe dehydration, persistent nausea, vomiting, and hypercalcemia, the patient received fluid resuscitation and Vit. D supplementation. A neck CT scan identified an 11 x 6 x 14 mm arterially hyperenhancing soft tissue structure at T1-T2, suggesting a probable parathyroid adenoma in the right paratracheal region. Management options included surgery or conservative therapy with fluids and Cinacalcet. A joint decision was made between Maternal Fetal Medicine, ENT and Endocrinology to proceed with parathyroidectomy. Surgical excision revealed an enlarged, hypercellular right inferior parathyroid gland (0.51g). Postoperative laboratory studies at 2 weeks showed normal PTH, Ca, Ionized Ca. Conclusion: It is preferable to conduct surgery for PHPT during the second trimester of pregnancy. However, when PHPT leads to severe symptoms, surgery might be considered in the third trimester. The severity of our patient’s symptoms led to inability to tolerate oral intake, deeming surgery necessary. The multidisciplinary team agreed that surgery in the third trimester would be the best course of treatment as it will result in normocalcemia immediately. Second trimester parathyroidectomy is viewed as safer due to the completion of organogenesis and lower teratogenicity risks. Performance of surgery during the third trimester may lead to an increase in the risk of premature birth. However, untreated hypercalcemia may increase fetal loss and thus third trimester parathyroidectomy can be considered as a treatment option for PHPT in pregnancy. It is also imperative to discuss all options with the patient. In our case, the patient had opted for surgery which was successful.
Presentation: 6/3/2024