Use of rhPTH(1-84) for hypoparathyroidism during early pregnancy and lactation

We present the first report of use of recombinant human parathyroid hormone (1-84) (rhPTH(1-84)) in a hypoparathyroid patient during early pregnancy and lactation. The patient developed postoperative hypoparathyroidism as a 28-year-old woman following total thyroidectomy for multinodular goiter. She was not well controlled with conventional therapy, and started rhPTH(1-84) in 2015 following its approval in the United States. She became pregnant in 2018 at age 40. She discontinued rhPTH(1-84) therapy at 5 weeks gestation but resumed in the postpartum period while breastfeeding. Her daughter's serum calcium was borderline elevated at 8 days postpartum but within the normal range at 8 weeks postpartum. The patient stopped nursing at around 6 months postpartum. Her daughter is now at 4 years and 5 months of age and is healthy and meeting developmental milestones. She was again pregnant at 8 months postpartum from her first pregnancy, and she made an informed decision to continue parathyroid hormone. At 15 weeks gestation, rhPTH(1-84) was recalled in the United States due to issues with the delivery device, and she discontinued rhPTH(1-84) treatment and resumed calcium and calcitriol supplements. She gave birth to a baby boy at 39 weeks in January 2020. At 3 years and 2 months of age, he is overall healthy. Further data are needed regarding the safety of rhPTH(1-84) in pregnancy and lactation. Learning points rhPTH(1-84) is approved for therapy of patients with hypoparathyroidism; however, there are no data regarding the safety of treatment during nursing and pregnancy. There are multiple alterations in mineral metabolism during normal pregnancy and lactation.