Intrauterine transfusions have been performed since 1963 as a therapeutic measure in erythroblastosis fetalis (1, 3). Prior to the instillation of packed red cells into the fetal peritoneal cavity, accurate needle placement is verified in most of the technics by a test injection of water-soluble contrast material (2). The following case is presented to illustrate the morphology demonstrated during such a procedure. A 27-year-old gravida III, para II was referred to the University of Iowa Hospital during the twenty-seventh week of her third pregnancy. Her first child was normal; the second child was erythroblastotic and required three exchange transfusions. Initially, a spectrophotometric analysis performed on a sample of amniotic fluid showed an abnormal peak, indicating a degree of fetal erythroblastosis. This optical density difference increased by the thirty-first week, and an intrauterine transfusion was performed in an effort to prolong gestation and save the child. A needle was directed over the reg...