Primary Hyperparathyroidism in Pregnancy

Primary Hyperparathyroidism in Pregnancy

Primary Hyperparathyroidism in pregnancy is a threat to the health of both mother and fetus. During pregnancy, more than 20 g of calcium is freely and rapidly transported from the mother into the fetus through the placenta. PTH has no effect on placental calcium transport. The low albumin levels, typically associated with pregnancy, are responsible for the low sensitivity of serum total calcium screening tests and may explain why up to 90% of Primary Hyperparathyroidism cases are undiagnosed until after a miscarriage. The risk for maternal and fetal complications cannot be predicted by duration of symptoms or serum calcium levels. The mothers suffer commonly from nephrolithiasis, hyperemesis, or even hypercalcemic crisis.


Persistent maternal hypercalcemia suppresses the development of the fetal parathyroid glands.Therefore, the most frequent serious complications of maternal hypercalcemia are neonatal hypocalcemia, ranging from neonatal tetany to stillbirth. Untreated disease will commonly complicate fetal development and fetal death is a significant risk.


The mothers suffer commonly from nephrolithiasis, hyperemesis, or even hypercalcemic crisis. The pregnant woman is at risk of hypercalcemic crisis after delivery. If the mother is untreated to term, sudden worsening of hypercalcemia can result from loss of the placenta and dehydration


Surgical treatment should be considered early, and a minimally invasive approach with ultrasound is best suited to mitigating risk to mother and fetus. Surgery during pregnancy is indicated for all patients with Primary Hyperparathyroidism, even if hypercalcaemia is mild and there are no established complications.

Parathyroidectomy should be performed during the second trimester in pregnant woman with symptomatic hyperparathyroidism. Parathyroidectomy can also be performed safely even in the third trimester by an experienced parathyroid surgeon, when symptomatic hypercalcemia occurs. However, symptom-free patients may be managed medically, allowing surgery to be postponed until after delivery


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2) Bendinelli C, Nebauer S, Quach T, McGrath S, Acharya S. Is minimally invasive parathyroid surgery an option for patients with gestational primary hyperparathyroidism? BMC Pregnancy Childbirth. 2013 Jun 11;13(1):130.

3) Sato K. Hypercalcemia during pregnancy, puerperium, and lactation: review and a case report of hypercalcemic crisis after delivery due to excessive production of PTH-related protein (PTHrP) without malignancy (humoral hypercalcemia of pregnancy). Endocr J. 2008 Dec;55(6):959-66.