Pregnant and hypercalcaemic: what next?

C Lim, F Palazzo, M Moriarty, S Jarvis, J Ostberg, A Sam

Watford General Hospital, and Hammersmith Hospital.

A 52 year-old female was referred with hypercalcaemia. She was 15 weeks pregnant with triplets following in-vitro fertilisation abroad. The patient was asymptomatic despite a serum calcium level of 3.08 mmol/L. Further investigations revealed a PTH of 22pmol/L, vitamin D of 25.1nmol/L and 24-hour urine calcium of 2.36mmol/L, consistent with a diagnosis of primary hyperparathyroidism. The neck ultrasound suggested an enlarged parathyroid at the inferior pole of the right thyroid lobe. The patient was treated with intravenous fluids and oral vitamin D supplements. The serum calcium improved though remained elevated at 2.76 mmol/L.

Following a multidisciplinary team meeting, she underwent surgery which was uneventful. Three normal glands were identified and the offending adenoma at the right inferior pole. The intraoperative PTH fell appropriately after removal of the abnormal parathyroid denoting cure. The evening of surgery corrected calcium level was normal at 2.37mmol/L with a PTH level of 0.7 pmol/L.  She was discharged home with standard follow up with normal biochemistry on day 1.

Primary hyperparathyroidism during pregnancy is rare, with less than 200 cases reported in the literature. Most common pHPT are caused by a single parathyroid adenoma and this also applies to pregnancy but targeted surgery is precluded by the contraindication of nuclear medicine studies. Primary hyperparathyroidism during pregnancy is associated with nausea, vomiting, anorexia and fatigue which may all exist in a normal pregnancy. Nephrolithiasis is the most common maternal complication followed by bone disease and pancreatitis. The most life-threatening complication is hypercalcaemic crisis. This is associated with 25% perinatal mortality and 50% neonatal tetany rate.

Foetal complications have been reported to be as high as 80%; mainly as a result of neonatal tetany. Other complications include premature birth, intra-uterine growth retardation and foetal death. Pregnant women with primary hyperparathyroidism should be offered surgical treatment in the second trimester of the pregnancy. During the first trimester, hypercalcaemia may be managed conservatively. In conclusion, primary hyperparathyroidism is rare during pregnancy. However, it is a preventable cause of foetal and maternal morbidity and mortality if recognised early and treated appropriately.