Ontogeny of Placental FcRn Protein During Human and Animal Pregnancy to Inform Developmental Toxicity Testing

Biologic therapeutics, including monoclonal antibodies, are increasingly important tools in modern medicine. For patients who are pregnant or may become pregnant, understanding how these therapies may transfer across the placenta is essential for interpreting developmental toxicity studies and informing human safety assessments.

A new publication from the HESI Global Developmental and Reproductive Toxicology (DART) Technical Committee provides important insights into this question. Published in Birth Defects Research, the paper, “Ontogeny of Placental FcRn Protein During Human and Animal Pregnancy to Inform Developmental Toxicity Testing,” reports findings from a collaborative, multi-sector experimental program focused on the neonatal Fc receptor (FcRn).

FcRn plays an important role in the transfer of Fc-containing biologics across the placenta during pregnancy. By mapping FcRn protein expression across multiple species and throughout gestation, the research provides new data to help scientists better understand placental transfer of these therapeutics. These findings may improve the interpretation of nonclinical developmental toxicity studies and support more informed human safety assessments for biologic medicines used during pregnancy.

Read the full publication: Bowman et al., 2026. Ontogeny of Placental FcRn Protein During Human and Animal Pregnancy to Inform Developmental Toxicity Testing. Birth Defects Research.  http://dx.doi.org/10.1002/bdr2.70058

Learn more about the HESI Global DART Technical Committee: https://hesiglobal.org/developmental-and-reproductive-toxicology-dart/