Subcutaneous Infusion of rhPTH1-34 During Pregnancy and Nursing in a Woman With Autosomal Dominant Hypoparathyroidism 1

We report a successful pregnancy in a young woman with autosomal dominant hypoparathyroidism type 1 (ADH1) due to an activating mutation of the calcium sensing receptor (CASR) (c.2519C>T; p.Ala840Val) who was treated with recombinant human parathyroid hormone (rhPTH)1-34 delivered via continuous subcutaneous infusion using an OmniPod pump. She experienced no tetany or hospitalizations during the pregnancy. Serum calcium levels ranged from 7.2 to 9.8 mg/dL. Due to mild preeclampsia, her infant was delivered at 37 weeks. There were no physical anomalies. The patient continued pump therapy while nursing her daughter, who was ultimately confirmed to have the same CASR mutation. Breastfeeding appeared to protect the infant from significant hypocalcemia without the need for calcium or calcitriol supplementation until weaning at a year of age. A role for parathyroid hormone-related protein (PTHrP) is suggested.