Endocrine Abstracts

Case history: A 30-year-old female was investigated and treated for hypercalcaemia during the third trimester of pregnancy. She has a background of rheumatoid arthritis on hydroxychloroquine and was reviewed by the rheumatologists during her pregnancy due to worsening limb and back pain. She had multiple calcium levels monitored during her pregnancy. Her calcium had been elevated since 2022 but had increased further during the pregnancy and it wasn’t until she was referred to the obstetricians during the third trimester that it was investigated further. She had significant symptoms of hypercalcaemia including bone pain, constipation, thirst and polyuria.

Investigations: Blood tests confirmed an adjusted calcium level of 2.99 mmol/l; a parathyroid hormone level of 12.4 pmol/l; a vitamin D level of 23 nmol/l; and normal thyroid function. A calcium creatine excretion ratio was 0.04. An ultrasound confirmed an enlarged lower left parathyroid gland. Genetic screening identified no genetic cause for hyperparathyroidism. Plasma metanephrines were normal. The results confirmed a diagnosis of primary hyperparathyroidism.

Results and treatment: She was admitted to the central delivery suite for intravenous fluids, and she was commenced on high dose vitamin D treatment. She was discussed in multidisciplinary team meetings with the regional maternal medicine network and endocrine surgeons. The limited evidence available for managing obstetric primary hyperparathyroidism suggests that parathyroidectomy should be considered in the second trimester. A decision was made to use the best medical approach. She developed proteinuria and was monitored for pre-eclampsia. Intravenous fluids were given cautiously. She was commenced on calcitonin. A caesarean section was performed at 37 weeks with no immediate complications. However, baby subsequently developed hypocalcaemia requiring paediatric input.

Points for discussion: This case questions whether similar cases are being missed if clinicians are unfamiliar with the importance of early detection of hypercalcaemia during pregnancy, and whether greater education is needed in order to avoid delayed presentations. Perhaps screening calcium levels in pregnant women during the initial ante-natal visits would be beneficial. Managing primary hyperparathyroidism in pregnancy is difficult, particularly if diagnosed in the third trimester. There is limited evidence with how to manage such cases and the evidence is primarily based on case reports. The complication of proteinuria made intravenous fluids difficult but there is limited evidence with regards to medications such as calcitonin and timing of delivery. Detailed guidelines for the management of primary hyperparathyroidism during pregnancy and postnatally would be helpful.