Primary hyperparathyroidism and Zollinger Ellison syndrome during pregnancy: a case report

SUMMARY: Multiple endocrine neoplasia type 1 (MEN1) is a rare inherited endocrine disorder with a high rate of penetrance. The incidence of MEN1 is 1/30,000 in the general population; however, it is quite rare for a patient to present for medical attention with MEN1 for the first time in pregnancy. Primary hyperparathyroidism (PHPT) is one of the most common features of MEN1. The incidence of PHPT occurring in pregnancy is 1%. Despite advances in the medical, surgical and obstetric care over the years, management of this condition during pregnancy may be challenging. It can be difficult to identify pregnant women with PHPT requiring intervention and to monitor safely. Hypercalcemia can result in significant maternal and fetal adverse outcomes including: miscarriage, intrauterine growth restriction, preterm delivery, neonatal hypocalcaemia, pre-eclampsia and maternal nephrolithiasis. Herein, we present a case study of a lady with a strong family history of MEN1, who was biochemically proven to have PHPT and evidence of Zollinger Ellison Syndrome (ZE) on endoscopy. This patient delayed her assisted pregnancy plans for in vitro fertilization (IVF) until completion of the MEN1 workup; nevertheless, she spontaneously achieved an unplanned pregnancy. As a result, she required intervention with parathyroidectomy in the second trimester of her pregnancy as her calcium level continued to rise. This case study highlights the workup, follow up and management of MEN1 presenting with PHPT and ZE in pregnancy. LEARNING POINTS: Women of childbearing age who are suspected to have a diagnosis of primary hyperparathyroidism ideally should have genetic testing and avoid pregnancy until definitive plans are in place. Zollinger Ellison syndrome in pregnancy means off-label use of high dose of proton pump inhibitors (PPI). Use of PPI in pregnancy is considered to be safe based on retrospective studies. Omeprazole, however, is FDA class C drug because of lack of large prospective studies or large case series during pregnancy. Calcium supplements in the form of calcium carbonate must be converted to calcium chloride by gastric acid in order to be absorbed, however, patients rendered achlorhydric as a result of PPI use will have impaired absorption of calcium. Therefore, use of calcium citrate might be considered a better option in this case.