Calcitriol administration during pregnancy in a partial DiGeorge anomaly

Abstract

A 23-year-old pregnant woman was known since birth to have partial DiGeorge syndrome with idiopathic hypoparathyroidism and clinically suspected thymus hypoplasia. The hypocalcaemia had until recently been treated with 1000 IU vitamin D3 daily. During the 9th week of pregnancy the serum calcium level was 1.9 mmol/l, the phosphate one 1.58 mmol/l and parathormone 5.6 pg/ml. To ensure better control, calcitriol was given (1.25-[OH]2-vitamin D3, initially 1 microgram daily and then, from the 22nd week of pregnancy onward, 1.5 micrograms daily), as well as calcium gluconate and lactate (initially 300 mg daily, then 900 mg daily). The serum calcium level at that time was between 2.0 and 2.5 mmol/l. Because of toxaemia of pregnancy the patient was hospitalized and confined to bed during the 37th week, whereupon the serum calcium level rose from 2.2 to 2.7 mmol/l, but a decrease in calcitriol dosage resulted in a decrease to within normal limits within one day. A girl was delivered by section in the 39th week: she had normal serum calcium and phosphate levels and appeared healthy.