Poster Presentation Australasian Diabetes in Pregnancy Society and Society of Obstetric Medicine Australia and New Zealand Joint Scientific Meeting 2021

Medical management of primary hyperparathyroidism in the third trimester of pregnancy: a case report (#115)

Jinghang Luo 1 , Esha Kathpal 1 , Jessica Deitch 1 , Devaang Kevat 1 , Vivian Grill 1 , Shane Hamblin 1 2 , Althea Askern 3 , Christopher J Yates 1 2
  1. Endocrinology and Diabetes, Western Health, Melbourne, VIC, Australia
  2. Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
  3. Women's and Children's Division, Western Health, Melbourne, VIC, Australia

BACKGROUND

Primary hyperparathyroidism during pregnancy is a rare condition with increased maternal and fetal risks. We report a case diagnosed at 33 weeks gestation that was managed conservatively.

CASE PRESENTATION

A 26-year-old primiparous woman was incidentally found to have a probable parathyroid adenoma on ultrasound at 33 weeks gestation, which had been performed to investigate a goitre and subclinical hyperthyroidism. She had asymptomatic hypercalcaemia, with a corrected calcium of 2.90mmol/L (albumin 29g/L, total calcium 2.64mmol/L, normal range 2.15–2.65mmol/L). Her ionised calcium and parathyroid hormone were also elevated (1.44mmol/L [1.15-1.29mmol/L], 14.8pmol/L [2.0-8.5pmol/L]). She had no family history of hypercalcaemia, hyperparathyroidism or related syndromes. Medications included cholecalciferol 2000 units/day for vitamin D deficiency (49nmol/L) and a pregnancy multivitamin.

The patient was initially managed with oral hydration as an outpatient for two weeks. At 35 weeks gestation, she was admitted due to increasing fatigue, polyuria, polydipsia (>4L/day) and persistent hypercalcaemia (correct calcium 2.86mmol/L), for intravenous and oral hydration. Intravenous saline (3L/day) in addition to oral intake (2L/day) failed to improve her ionised calcium and therefore furosemide 40mg BD was commenced on day 3 of admission, with near-normalisation of calcium levels (ionised calcium 1.31 mmol/L). Although the patient developed peripheral oedema, she did not develop hypertension, pre-eclampsia or pulmonary oedema, and will have induction-of-labour at 37 weeks with postpartum neonatal assessment for hypocalcaemia.

DISCUSSION

Primary hyperparathyroidism in pregnancy has been associated with a 3.5-fold risk of miscarriage in the first and second trimesters1. Parathyroid surgery is recommended in the second trimester; there is no consensus on surgery in the third trimester. Pre-eclampsia occurs in up to 30% of medically managed cases, and severe neonatal hypocalcaemia has been reported2.  Our case is notable for the significant improvement in calcium following furosemide administration, a loop diuretic that inhibits renal paracellular reabsorption of calcium.

REFERENCES

  1. Norman J, Politz D, Politz L. Hyperparathyroidism during pregnancy and the effect of rising calcium on pregnancy loss: a call for earlier intervention. Clin Endocrinol (Oxf). 2009;71(1):104-109. doi:10.1111/j.1365-2265.2008.03495.x
  2. Rigg J, Gilbertson E, Barrett HL, Britten FL, Lust K. Primary Hyperparathyroidism in Pregnancy: Maternofetal Outcomes at a Quaternary Referral Obstetric Hospital, 2000 Through 2015. J Clin Endocrinol Metab. 2019;104(3):721-729. doi:10.1210/jc.2018-01104