Hypercalcaemia due to parathyroid carcinoma presenting in the third trimester of pregnancy.

Primary hyperparathyroidism (pHPT) in pregnancy may be associated with significant maternal and fetal morbidity and mortality. Medical management of pHPT in pregnancy is limited, and surgery is the only definitive therapeutic option. The ideal timing for surgery is mid-second trimester, but surgery may also be safely performed in the third trimester. Delayed parathyroid surgery may result in a hypercalcaemic crisis postpartum owing to loss of active placental calcium transfer. We present a case of parathyroid carcinoma in pregnancy presenting with pre-eclampsia at 32 weeks' gestation.