Administration of rituximab during the first trimester of pregnancy without consequences for the newborn.

Rituximab, a chimeric mouse/human monoclonal antibody that binds to the CD20 antigen, is part of current treatment of many B-cell malignancies and several autoimmune diseases. Very few cases of rituximab administration during pregnancy have been described. We report here the case of rituximab administration during the first trimester of pregnancy in a woman with autoimmune hemolytic anemia. No significant effects were observed in B-cell counts or the immune status of the newborn.