Winrho: Safety and Efficacy during Pregnancy

Anti-D (WinRho SDF Baxter) immune globulin is approved in the United States for the treatment of chronic and acute ITP in adult and children. It is also approved for the suppression of Rh isomimmunization in pregnant women. The use of Anti-D for ITP during pregnancy is not licensed in the United States. In pregnant patients in particular, treating physicians are wary of the use of a drug in an off-label setting given the fear of increased risk to the mother and fetus. To assess its use in pregnant patients a surveillance questionnaire was sent to over 700 practicing adult or pediatric hematologists and obstetricians in the United States. A computer based literature search using the search terms “ITP and pregnancy” and “Anti-D and pregnancy” was also conducted.

Very few pregnant patients with ITP appear to have been treated with Anti-D. Information on 10 cases were obtained for review related to the efficacy and safety of Anti-D to mother and child.

Maternal Adverse Events included: headache (2 patients), nausea (1 patient), hemolysis (1 patient), and myalgias (1 patient). Fetal adverse events included fetal jaundice in one child. Concomitant medications included prednisone and IVIG.

A majority of these patients were treated during the third trimester of pregnancy. Out of the 10 patients, all patients achieved a platelet count greater than 30,000. Many of these patients were on concomitant medications for ITP, and were initiated on Anti-D in an attempt to raise the platelet count. There were no episodes of DIC, renal failure, fetal death, neonatal hemolysis or spontaneous abortion. One child had jaundice, which resolved with phototherapy and there was no long-term sequelae. This review provides some data for the efficacy and safety of anti-D for pregnant patients with ITP. Further investigation of its use during pregnancy is on-going. These data should encourage larger studies so this indication can be considered for approval