LAUSR

We, the investigators of the National Transplantation Pregnancy Registry (NTPR), read with concern King and colleagues’ Pregnancy Outcomes Related to Mycophenolate Exposure in Female Kidney Transplant Recipients [1], based on a limited subset of our data, which concludes that first trimester exposure to mycophenolate (MPA) may not be associated with increased fetal risks. We disagree with their interpretation of the data and feel strongly that their conclusions convey false information regarding MPA safety during pregnancy. In contrast, our analysis of this data finds: (1) the significant risks to pregnancies exposed to MPA any time in the first trimester are miscarriage and phenotypic birth defects, and (2) no association between discontinuing MPA products <6 weeks preconception and the risk of graft loss at 5 years. We attribute the authors’ invalid conclusions to systematic errors in assigning recipients to their comparison groups and missing information. This article is protected by copyright. All rights reserved.