Introduction
Primary hyperparathyroidism in pregnancy is rare, with an estimated prevalence of 1%.1 Symptoms of hypercalcaemia are often non-specific in pregnancy.2 At calcium levels >2.86mmol/L, a 3.5-fold increase in pregnancy loss is observed in those with primary hyperparathyroidism.3 Curative parathyroidectomy is often delayed until the second trimester of pregnancy given the theoretical risk of miscarriage with anaesthesia and surgery.4 However, hypercalcaemic-related miscarriages often occur during first, or early second trimester of pregnancy; suggesting the need for earlier intervention.3
Case Presentation
We describe a case of a 37-year-old woman who underwent a successful parathyroidectomy at six weeks gestation for primary hyperparathyroidism.
M.M. initially presented with anxiety, malaise and a three-week prodrome of constipation and polydipsia, despite consuming 3L of water a day. On examination, she was normotensive with no palpable neck masses or lymphadenopathy. She had a miscarriage four months prior, whereby a corrected calcium was elevated at 3.06mmol/L.
Serial biochemistry was consistent with primary hyperparathyroidism; corrected calcium of 3.16mmol/L, PTH 27.6pmol/L, phosphate 0.75mmol/L, ALP 72U/L and Vitamin D 53nmol/L. Serum Beta-CTx was 1500ng/L and urine calcium:creatinine ratio was 1033mmol/mol (see Table 1).
A 20x6x8mm parathyroid gland was localised on ultrasonography and she underwent a minimally invasive parathyroidectomy two days after her initial presentation. Successful resection of the lesion was demonstrated by an intraoperative PTH fall from 21.4pmol/L to 3.6pmol/L over ten minutes. She experienced no post-operative complications and was discharged 2 days after surgery. She continues to progress well through her pregnancy.
Currently, no guidelines exist for managing primary hyperparathyroidism in pregnancy. Only two cases of parathyroidectomy in first trimester of pregnancy have been described.5,6 Our case report and literature review add additional insight into the growing body of evidence surrounding the safety of early surgical intervention in severe symptomatic primary hyperparathyroidism to prevent adverse maternal-foetal outcomes.