PURPOSE: to evaluate the effect of intravascular transfusion on ductus venosus and inferior vena cava Doppler ultrasound indexes (SV/CA) and to relate it to hemoglobin levels before transfusion. METHODS: this is a transversal prospective study. A total of 62 intravascular transfusions were performed in 27 fetuses from pregnancies with red blood cell isoimmunization. The 62 cases were divided into two groups: (1) fetuses with hemoglobin levels before transfusion <FONT FACE=Symbol>£</FONT>10 g/dL and (2) fetuses with hemoglobin levels before transfusion >10 g/dL. The SV/CA and CA/SV indexes were measured using color Doppler ultrasound 6 h before and 12 h after intravascular transfusion. The index values before and after transfusion in all 62 cases were compared. Thereafter we compared these indexes before and after transfusion regarding each group. The Wilcoxon test was used and the results were considered statiscally significant when p<0.05. RESULTS: when we studied the whole group (62 cases) no significant difference was observed between the CA/SV index before and after transfusion (p=0.775). On the other hand, a significant increase in the SV/CA index was observed after transfusion (p=0.004). No significant differences were observed in both the SV/CA and CA/SV indexes before and after transfusion in the group of fetuses with hemoglobin levels before transfusion <FONT FACE=Symbol>£</FONT>10 g/dL (p=0.061 and p=0.345, respectively). There was a significant increase in the CA/SV index after transfusion in fetuses with hemoglobin levels before transfusion >10 g/dL (p=0.049), but the SV/CA index did not change in this group (p=0.086). CONCLUSION: venous Doppler study may be useful to understand fetal hemodynamic adjustment after intravascular transfusion. An increase in SV/CA without change in CA/SV after transfusion in anemic fetuses may be an important compensatory mechanism to increase intravascular volume. The increase in CA/SV index in fetuses with hemoglobin levels before transfusion <10 g/dL suggests a state of fetal hypervolemia.
Intrauterine blood transfusion; Maternal-fetal isoimmunization, venous; Doppler ultrasound
