Primary hyperparathyroidism in pregnancy is rare and if untreated is associated with high maternal and fetal morbidity and mortality.
We report the case of a 30 year old woman who presented at 25 weeks gestation in her second pregnancy with fatigue, nausea and vomiting. She had no previous medical history and had an uncomplicated pregnancy prior to presentation. Her only medication was a multivitamin. Initial investigations included blood tests which revealed significant hypercalcaemia with a corrected calcium of 3.39 mmol/L (range 2.15 – 2.55mmol/L), an ionized calcium of 1.89 mmol/L (range 1.13 – 1.32mmol/L) and a low phosphate level 0.72mmol/L (range 0.87 – 1.45mmol/L). Her PTH was inappropriately high at 8.7 pmol/L (range 1.6 – 6.0pmol/L) and she was vitamin D deficient with a level of 17nmol/L (range >75 nmol/L). A diagnosis of primary hyperparathyroidism was made. She was initially treated with intravenous normal saline and oral frusemide with only modest improvements in her serum calcium level. A neck USS revealed a right parathyroid mass. She was reviewed by the General Surgery team from the attached tertiary hospital and underwent a right neck exploration on day 7 of admission. An enlarged right inferior parathyroid gland was excised with no post-operative complications. Histology was consistent with a parathyroid adenoma. She was commenced on calcium carbonate post operatively. She went into premature labour at 33 weeks and 3 days and went onto have an emergency caesarean section. The infant’s calcium level at birth was normal.
Primary hyperparathyroidism is uncommon during pregnancy however severe hypercalcaemia is associated with significant maternal and fetal risks. In case series maternal complications included hyperemesis, nephrolithiasis, recurrent UTI and pancreatitis. Neonatal complications included hypocalcaemia and tetany secondary to fetal PTH suppression, preterm delivery, low birth weight and fetal loss.1,2 Surgery during the second trimester is the preferred treatment for symptomatic patients.