Summary

Primary hyperparathyroidism is rare during pregnancy. Recognition may be challenging as symptoms overlap with those of other common disorders of pregnancy. Furthermore, physiological changes of pregnancy affecting calcium homoeostasis mean awareness of the condition and careful interpretation of results in the light of pregnancy are essential for diagnosis. Maternal complications of primary hyperparathyroidism include nephrolithiasis, pancreatitis, cardiac arrhythmias, hypertension and peptic ulcers. At its most severe, hypercalcaemic crisis may occur, presenting with acute neurological disturbance. Most commonly, the underlying aetiology is a solitary parathyroid adenoma whereby parathyroidectomy is the only cure. A 30-year-old Caucasian woman booked under Consultant care presented at 32 weeks gestation with vomiting and right-sided loin pain. Following presentation, she was diagnosed with renal calculi. She was delivered by caesarean section (CS) due to deterioration in renal function. Post-CS, she had a grand mal seizure. She was found to have hypercalcaemia with underlying hyperparathyroidism.