Primary Hyperparathyroidism in Pregnancy

Abstract

The diagnosis of gestational primary hyperparathyroidism (PHPT) is based on elevated serum calcium and PTH levels but is complicated by several physiologic changes including hypoalbuminemia, increased glomerular filtration, transplacental transfer of calcium, and increased estrogen levels which lower maternal serum calcium levels. PHPT during pregnancy is associated with several risks to the mother (hyperemesis, nephrolithiasis, mental status changes, muscle weakness, and rarely pancreatitis) and fetus (neonatal hypoparathyroidism, hypocalcemia, tetany, low birth weight, preterm delivery, and miscarriage), especially when maternal total serum calcium is >11 mg/dL. While clear treatment guidelines for PHPT in pregnancy are lacking, parathyroidectomy (ideally in the second trimester) is often performed to prevent associated risks. If surgery is not performed during pregnancy, neonates should have their serum calcium monitored, with awareness that hypoparathyroidism may not be present in the immediate postpartum period.