Primary hyperparathyroidism during pregnancy.

PURPOSE: Primary hyperparathyroidism (pHPT) during pregnancy is rare and associated with increased morbidity and mortality for both mother and fetus. This review aims to draw together recent thinking on pregnancy and pHPT.

METHODS: We have performed a Pubmed (Medline(®)) search with no time limit using "primary hyperparathyroidism", "pregnancy" or "management" as keywords. We reviewed 37 articles in English and French languages on pHPT characteristics, clinical presentations, pregnancy complications, birth outcomes and management of pHPT during pregnancy.

RESULTS: The diagnosis of pHPT is characterized by an elevated serum calcium level associated with an inappropriate increase in the parathyroid hormone level. The clinical manifestations are directly related to the calcium level. Usual techniques to detect parathyroid adenoma or hyperplasia, as computerized tomography and 99mTc-sestamibi scintigraphy, are not recommended in pregnancy. Thus, ultrasonography of the neck is the current first-line investigation during pregnancy for localization of parathyroid diseases. pHPT during pregnancy with mildly elevated calcium levels may be managed with medical treatment: intravenous or oral rehydratation, with or without forced diuresis. Few drugs are available for pHTP during pregnancy; calcitonin and cinacalcet require further study; bisphosphonate should be restricted to life-threatening hypercalcemia. Surgery is the only curative treatment and is recommended when calcium levels are above 2.75 mmol/L. It should be performed in the second trimester and considered in the third trimester if there is inadequate response to medical therapy.

CONCLUSION: Early diagnosis of pHPT in a pregnant woman, followed by appropriate management and treatment, has been shown to significantly reduce maternal and fetal complications.