Follow-up and Clinical Management of a Pregnant Woman with Primary Hyperparathyroidism Associated with Multiple Endocrine Neoplasia Type 1: A Case Report

Introduction: Studies on clinical implications and management of endocrine tumors in pregnant women with Multiple Endocrine Neoplasia Type 1 (MEN1) are limited to case reports or small series, which challenges individualized treatment decision making. Potential risks of maternal and fetal complications related to MEN1 neoplasms, such as primary hyperparathyroidism (PHPT) and prolactinoma, are primarily known from studies on sporadically occurring tumors. Case Description: A 38-year-old woman with MEN1 developed mild and sustained hypercalcemia (serum calcium: 10.36 ± 0.32, 9.9-10.8 mg/dL) due to PHPT, throughout her pregnancy, leading to careful periodic laboratory surveillance without specific therapeutic intervention. Progressive intrauterine fetal growth restriction during the third trimester resulted in a cesarean section birth at term (at 38 weeks and 4 days) of a low birth weight for gestational age newborn (< 3rd percentile: 2115 grams). Conclusions: This case highlights the need for monitoring the progression of intrauterine growth in pregnant women with PHPT associated with MEN1. Since there are no established guidelines for the clinical or surgical management of PHPT in pregnant women with MEN1, treatment decisions should be individualized and made by a specialized multidisciplinary team, based primarily on experience, albeit limited, from sporadic cases of PHPT.