Endocrine Abstracts

We report a 32-year-old primigravida with type 2 diabetes and large uterine fibroid who was found to have incidental, asymptomatic, non-PTH driven hypercalcaemia of 2.67 mmol/l (NR 2.2-2.60 mmol/l) at 7 weeks gestation. Investigations revealed no evidence of malignancy. Interestingly, following initial blood test, her calcium normalised but with persistent complete suppression of PTH until 19 weeks gestation, when her calcium rose to 3.25 mmol/l. Her 1,25-dihydroxy Vitamin D was elevated at 278 pmol/l (NR 43-144 pmol/l) along with raised inflammatory markers. However, further biochemical tests and CT chest ruled out sarcoidosis, tuberculosis and lung malignancy. We considered the possibility of PTH-related peptide (PTHrP)-driven hypercalcaemia secondary to her large uterine fibroid. PTHrP levels were not available for testing nationally. Her hypercalcaemia could only be managed by intravenous fluid hydration. She had multiple admissions for this. Management proved to be a challenge due to development of pregnancy induced hypertension. Calcitonin was considered but dismissed at that stage in pregnancy due to limited duration of action and uncertain risk to foetus. Between 27-33 weeks gestation, she managed to keep her calcium levels around 2.7-2.8 mmol/l with 4ls/day oral hydration. Foetal growth was at 10th centile but stable and diabetes was well controlled. At 35+6 weeks, her calcium was at its highest level at 3.88mol/l. We were unable to give adequate IV hydration due to development of pre-eclampsia. She was treated with calcitonin, lowering calcium to 3.09 mmol/l. Decision was made for induction but due to foetal distress; she had an emergency caesarean section. She delivered a healthy baby boy. Her calcium normalised a week later. This case highlights the rare cause of hypercalcaemia likely mediated by PTHrP due to enlarging uterine fibroid in pregnancy. We would like to share our experience in the challenges of investigating and managing hypercalcaemia in pregnancy given the limited investigation/treatment modalities available.