MANAGEMENT OF HYPOPARATHYROIDISM DURING PREGNANCY REPORT OF 12 CASES

There is no established therapeutic regimen for treatment of hypoparat hyroidism during pregnancy. This is due particularly to uncertainty ab out the use of vitamin D or its analogues, as in animal experiments te ratogenic side-effects have been reported. Nevertheless, vitamin D or its analogues are required to control tetany predisposing to abortion and preterm labour, We herein report the course of two pregnancies in a hypoparathyroid woman treated with calcitriol (1,25(OH)(2)D-3). Addi tionally, we describe the outcome of pregnancy in ten women receiving calcitriol, reported to the Drug Safety Department (DSD), Hoffmann-La Roche AG. A 29-year-old hypoparathyroid woman receiving chronic treatm ent with calcitriol (0.25 mu g/day) and calcium (1.5 g/day) was referr ed in the Gth week of her first pregnancy. Calcitriol was initially di scontinued, but during the 20th week of pregnancy recurrent tetany occ urred (serum calcium 1.74 mmol/l). Calcitriol (0.25 mu g/day) was adde d, stabilizing serum calcium around 2.15 mmol/l with 1,25(OH)(2)D-3 co ncentrations around 60 ng/l (normal range 35-80 ng/l). To maintain nor mocalcaemia the calcitriol dose was increased to 0.5 mu g/day during t he 33rd week and to 0.75 mu g/day shortly before delivery of a healthy girl in the 37th week. During her second pregnancy-calcitriol was giv en initially at a dose of 0.25 mu g/day with further adaptation to 0.5 mu g/day during the 20th and to 1.00 mu g/day in the 31st week, Serum calcium and 1,25(OH)(2)D-3 were continually within the lower normal r ange. She gave birth to another healthy girl during the 39th week. In eight of the ten pregnancies reported to the DSD no adverse effects of calcitriol (0.25-3.25 mu g/day) were seen and healthy babies were del ivered. In two retrospectively reported cases, serious adverse events were described: premature closure of the frontal fontanelle, and still birth in the 20th week due to complex fetal malformation respectively. However, in both cases the causative role of calcitriol administratio n remains highly questionable. We conclude that, during pregnancy, man agement of maternal hypoparathyroidism with calcitriol and calcium is feasible, if the 1,25(OH)(2)D-3 concentrations are adapted to the phys iological needs during pregnancy and serum calcium levels are kept in the lower normal range.