Changes in treatment needs of hypoparathyroidism during pregnancy and lactation: A case series.

OBJECTIVE: As only sparse data are available, we aimed to investigate whether needs for activated vitamin D and calcium supplements change in women with hypoparathyroidism during pregnancy and lactation and risk of pregnancy-related complications. DESIGN: Retrospective review of medical records. PATIENTS: Twelve Danish and Canadian patients with chronic hypoparathyroidism who completed 17 pregnancies. MEASUREMENTS: Data were extracted on plasma levels of ionized calcium (P-Ca2+ ) and doses of active vitamin D and calcium supplements during pregnancy (N = 14) and breastfeeding (N = 10). Data on pregnancy complications were available from all 17 pregnancies. RESULTS: Although average doses of active vitamin D (P = .91) and calcium supplements (P = .43) did not change during pregnancies, a more than 20% increase or decrease in dose of active vitamin D was needed in more than half of the pregnancies in order to maintain normocalcemia. Five women (36%) developed hypercalcaemia by the end of pregnancy or start of lactation. Median levels of P-Ca2+ increased from 1.20 mmol/L in third trimester to 1.32 mmol/L in the post-partum period (P < .03). Accordingly, the average dose of active vitamin D was significantly reduced (P = .01) during lactation compared to 3rd trimester. One woman developed severe pre-eclampsia (6%). Further four pregnancies (24%) were complicated by polyhydramnios, dystocia and/or perinatal hypoxia. Ten pregnancies required caesarean delivery (59%) with four (24%) being performed as an emergency. CONCLUSION: In chronic hypoparathyroidism, close medical monitoring of the mother with frequent adjustments in the dose of calcium and active vitamin D is required during pregnancy and lactation in order to maintain normocalcemia. Patients should be offered close obstetric care to handle potential perinatal complications. We recommend evaluating the neonate immediately after birth and notifying the paediatrician of the risks of hypocalcaemia as well as hypercalcaemia in the neonate.

Canadian national hypoparathyroidism registry: an overview of hypoparathyroidism in Canada.

PURPOSE: To evaluate the epidemiology, presentation and management of hypoparathyroidism in Canada. Hypoparathyroidism is associated with significant morbidity and poor quality of life. We present baseline results from the Canadian National Hypoparathyroidism Registry, a prospective observational study evaluating hypoparathyroidism in Canada. METHODS: Our study enrolled 130 patients with hypoparathyroidism. Patients were followed every 6 months with clinical and lab assessments. We present baseline data in this manuscript. RESULTS: Seventy percent (91/130) of patients had postsurgical hypoparathyroidism, 30% (39/130) of patients had nonsurgical hypoparathyroidism due to autoimmune, genetic or idiopathic causes, and a molecular diagnosis was confirmed in 11 of these 39 patients. Pseudohypoparathyroidism was confirmed in 4/39 patients, DiGeorge syndrome in 2/39 patients, Barakat syndrome with a mutation in the GATA3 gene in 1/39, and activating mutations of the CASR gene in 3/39 patients with nonsurgical hypoparathyroidism. Renal complications with nephrocalcinosis or nephrolithiasis were present in 27% (14/52) of patients with postsurgical disease and 17% (4/24) of patients with nonsurgical hypoparathyroidism. Basal ganglia calcification was noted on imaging in 15% (n = 5/34) of patients with postsurgical hypoparathyroidism and 37% (n = 7/19) of patients with nonsurgical hypoparathyroidism. CONCLUSIONS: Hypercalciuria was more commonly seen in those with renal complications of nephrocalcinosis, nephrolithiasis or CKD, and hyperphosphatemia was more commonly seen in those with basal ganglia calcification. Hospitalization occurred in 28% of those with postsurgical hypoparathyroidism and 46% of those with nonsurgical hypoparathyroidism. Hypoparathyroidism is associated with significant morbidity. Effective strategies to reduce the short-and long-term complications of hypoparathyroidism need to be developed and evaluated.