Endocrine Abstracts

JOINT1039

Introduction: Primary hyperparathyroidism in pregnancy is rare, with a reported incidence of 1%. Hunter and Turnbull documented the first case of hyperparathyroidism in pregnancy in 1931. Maternal and fetal/neonatal complications are estimated to occur in 67 and 80% of untreated cases respectively. Maternal complications include nephrolithiasis, pancreatitis, hyperemesis gravidarum, pre-eclampsia and hypercalcemic crises. Fetal complications include intrauterine growth restriction; preterm delivery and a three to five-fold increased risk of miscarriage, while neonatal complications include hypocalcaemia. We present a case of hyperparathyroidism successfully treated by surgery during second trimester.

Clinical case: 41 y.o woman, with background of hyperparathyroidism diagnosed by combination of high adj Ca - 2.90 mmol/l(2.2-2.6), high PTH 12.6pmol/l(1.6-6.9) along with normal Vitamin D and high urine calcium/creatinine ratio 0.035. US parathyroid and spect –CT scan confirmed diagnosis of left lower parathyroid adenoma. She found to be pregnant while awaiting surgery. During pregnancy her calcium level reached up to 2.97 mmol/l with PTH 117 ng/dl (15-65), which lead to the decision to perform surgery in second trimester. Post op histology was consistent with parathyroid adenoma, but patient remained hypercalcaemic up to 2.91 mmmol/l despite of high fluid intake. Repeated US scan showed residual left inferior parathyroid lesion measuring 12 mm and small ill-defined sub-centimetre thyroid nodule U2/U3. Subsequently, she had re-operative parathyroidectomy and left thyroid lobectomy with significant drop of PTH during surgery. Her PTH level normalised and adj Ca dropped to 2.5 and remained at this level until the end of pregnancy. Histology confirmed parathyroid adenoma tissue within scar tissue and 1 mm micro classical parathyroid carcinoma (pT1a). Had successful pregnancy without complications, apart from GDM, which ended up by elective caesarean section on time with normal baby. Her calcium level after pregnancy remains within normal limits.

Discussion: Parathyroidectomy is the definitive treatment for primary hyperparathyroidism and is recommended in pregnancy when serum calcium is greater than 2.75 mmol/l, particularly in patients with prior pregnancy loss. Retrospective data have demonstrated that patients treated with parathyroidectomy have lower rates of pre-eclampsia and preterm delivery compared to patients managed medically. Surgery is preferably performed in the second trimester due to incomplete organogenesis in the first trimester, and the risk of preterm delivery in the third trimester. Our case is also showing successful outcome of pregnancy treated with surgery, which allowed to avoid maternal and fetal complications. Concomitant finding of papillary thyroid cancer during pregnancy helped to avoid further thyroid surgery.