Ultrasound contributions to the management of the severely isoimmunized fetus.

Twenty-four out of 81 fetuses affected by anti-D isoimmunization underwent ultrasonic guided intrauterine transfusions (2.8 I. U. T.s per fetus). The absolute value and trend of delta OD 450 micron value was correlated with the severity of fetal condition as evaluated by ultrasonography following simple semiquantitative grading of ascites (mild, moderate, severe) and diagnosis of hydrops. The evaluation of disease was monitored in this way during transfusion therapy. Transfusion procedures have been ultrasonically guided. When ascites was present a few milliliters of isolytic solution allowed the bubbling effect to be observed. In the case of no ascites we confirmed the needle positioning by a cineradiographic sequence lasting a few seconds. Fetal transfusions were repeated every 10 to 15 days and the amount of packed red cells to be injected was determined according to the week of gestation. Post-transfusion monitoring included ultrasonic reevaluation of fetal parameters and non-stress testing. All fetuses were delivered via cesarean section before the 35th week of gestation. In no case was treatment started after the 31st week. Seventeen fetuses were transfused before the 26th week (71%). In 13 fetuses transfusions were started before ascites had appeared. Only 5 fetuses worsened and the 3 which became hydropic eventually died. The delta OD-450 value of these 5 cases before therapy had already indicated that they were more severely affected. Survival rate in this group was 69%. Eleven fetuses showed different degrees of ascites or hydrops at the time of the first transfusion.(ABSTRACT TRUNCATED AT 250 WORDS)