Management of pregnancies complicated by anti-c isoimmunization

OBJECTIVE: To review cases of anti-c isoimmunization and determine the most appropriate management strategies. METHODS: We performed a review of 102 pregnancies managed at The Ohio State University from 1967 to 2001 for anti-c isoimmunization. Of these, 55 had complete data and are included in this report. Information collected included serum titers, DeltaOD(450) values, Liley zones, fetal and neonatal hemoglobin levels and antigen typing, neonatal direct antiglobulin test, and neonatal outcomes. The appropriateness of traditional management was then evaluated. RESULTS: Of the 55 pregnancies, 46 had fetuses with positive direct antiglobulin test, and nine pregnancies had unaffected fetuses. Of the affected neonates, 12 (26%) had serious hemolytic disease of the newborn. Of these 12, 8 required fetal transfusion, and the remaining 4 newborns had hemoglobin levels of less than 10 g/dL at the time of delivery. A titer of 1:32 or greater or the presence of hydrops fetalis identified all such fetuses. There were 58 amniocenteses performed for DeltaOD(450) When plotted on modified Liley graphs, DeltaOD(450) values corresponded to disease severity. There were no perinatal deaths attributable to anti-c hemolytic disease of the newborn. CONCLUSION: Anti-c isoimmunization might cause significant fetal and newborn hemolytic disease. A titer of 1:32 or greater or evidence of hydrops fetalis identified all the serious hemolytic disease at our institution. The significance of antibody titers and DeltaOD(450) values was similar to Rh-D sensitized pregnancies, and management by the same modalities is appropriate. (Obstet Gynecol 2004; 103:24-30. (C) 2004 by The American College of Obstetricians and Gynecologists).