We present a case of primary hyperparathyroidism in a pregnant woman presenting with recurrent vomiting.
A 34 year-old Asian woman was admitted with nausea and vomiting at 8 weeks gestation. Clinical examination was unremarkable apart from dehydration. Electrolytes and thyroid function were within normal limits. A diagnosis of hyperemesis gravidarum was made and patient was discharged after rehydration. Over the next eight weeks she presented with similar symptoms and outcome on three further occasions. She was readmitted and her calcium was checked on a routine biochemistry screen. She was found to be hypercalcemic: Ca 3.02 (2.12.6) mmol/L, Alb 30 (3547) g/L, K 2.7 (3.65.3) mmol/L with a raised PTH of 73.3(0.455.00) pmol/L, confirming primary hyperparathyroidism.
On further questioning, she complained of weight loss, tiredness, and myalgia. Ultrasound of her neck demonstrated a 25×12×6 mm lesion at the left lower pole of thyroid. In view of her on-going symptoms and persistantly high calcium, she was referred for parathyroidectomy, which was performed under local anaesthesia and regional cervical block, during her 21st week of pregnancy. Frozen section and later histology confirmed parathyroid adenoma. Her calcium post-operatively was 1.93 mmol/L and she was commenced on calcium and α-calcidol. The rest of her pregnancy was uneventful and she had a normal delivery of a healthy baby girl weighing 2680 g, with normal Apgar score, at 39/40.
Untreated hyperparathyroidism in pregnancy is associated with complications in up to 67% of mothers and 80% of infants. This case adds to the evidence that surgery in the second and third trimester is safe and reduces the risk of complications. Post-operative hypocalcemia in both mother and infant is common, but easy to manage with oral calcium and vitamin D. This case also illustrates the importance of measuring serum calcium in a pregnant woman who has severe or prolonged hyperemesis gravidarum.