Fetal transfusion for red blood cell alloimmunization in pregnancy

Objective: To present an up-to-date review of the literature encompassing all important aspects of fetal transfusion for red blood cell alloimmunization in pregnancy. Data Sources: A MEDLINE computer data base search was conducted for pertinent articles through August 1995. Additional publications were identified by cross-referencing. Methods of Study Selection: All pertinent references were reviewed by the authors, and their clinical significance in the fetal treatment of red blood cell alloimmunization was summarized. Tabulation, Integration, and Results: Fetal intraperitoneal transfusion in the treatment of severe red blood cell alloimmunization was first reported by Liley in 1963. Since then, major advancements have included intravascular techniques and fetal paralysis. A total of seven different approaches have been used. Case series describing fetal intravascular transfusion were reviewed, and outcomes were analyzed for all pregnancies and, separately, for those presenting with and without hydrops fetalis. Eighty-four percent of 411 fetuses that underwent intravascular transfusion had good outcomes. Ninety-four percent of nonhydrophobic fetuses and 74% of hydropic fetuses survived. Those with severe anemia but no hydrops at transfusion were five times more likely to survive than fetuses already hydropic. Conclusion: For pregnant patients presenting with severe red blood cell alloimmunization remote from term, fetal transfusion remains the best available therapeutic option. It is a safe procedure with a perinatal loss rate of approximately 1-3%, and overall neonatal survival exceeds 80%. It is the best available option until red blood cell alloimmunization can be prevented altogether.