568 The association of oligohydramnios with fetal nucleated red blood cell count

OBJECTIVE:The purpose of this investigation is to evaluate maternal alloimmunization to paternal antigens as a treatment for hemolytic disease of the fetus/newborn (HDN) in the rabbit model.STUDY DESIGN: Fourteen does and matched RBC incmnpatible bucks underwent the experimental protocol.We compared fetal hematologic parameters ffonl unaffected litters to affected litters (following alloimmunization to RBC antigens) and affected litters following alloimnmnization to paternal leukocytes.Alloimmunization to both RBC antigens and WBC antigens was achieved through multiple subcutaneous and intravenous injections.Paternal lenkocytes were harvested from matched, incompatible bucks after pretreatment with recombinant-hmuan Growth stimulating Factor (RhG-CsF).On gestational day#28, ultrasound-guided intracardiac blood sampling was performed on all litters, and does underwent anti-WBC and RBC antibody titers.Generalized estimating equations (GEE) were used for statistical analysis due to correlated data, both using imnmnization status as a predictor variable with fetal hematologic parameters as outcomes and to analyze the effect of log transformed RBC and WBC titers on fetal hemoglobin.A P value of