Fetal cardiac contractility before and after intrauterine transfusion.

Objective To evaluate the effect of fetal anemia and intrauterine transfusion on ventricular shortening fraction. Methods The end-diastolic and end-systolic transverse dimensions of the left and right ventricles were obtained using M-mode ultrasonography. The shortening fractions of both ventricles were calculated at three time points: before, immediately after and one day after intrauterine transfusion. The blood volume given at intrauterine transfusion was expressed as a percentage of estimated fetoplacental blood volume. Results Complete measurements were obtained from 49 transfusions in 23 fetuses. Intrauterine transfusion was performed at a median gestational age of 31 (range, 19–35) weeks. Median hemoglobin concentration before and after intrauterine transfusion was 7.9 (range, 2.7–13.7) g/dL and 14.3 (range, 12.7–16.1) g/dL, respectively. Both left and right ventricular shortening fractions differed significantly between the three time points. Left ventricular shortening fraction decreased immediately after transfusion in 43 (88%) of the 49 procedures. Right ventricular shortening fraction decreased immediately after transfusion in 42 (86%) of the 49 procedures. At the first intrauterine transfusion, there was only a weak correlation between the decrease in shortening fraction of both ventricles and the transfused volume (left: R2 = 0.15; P = 0.20/right: R2 = 0.005; P = 0.81). Conclusion Transfusion significantly decreases the shortening fraction of both ventricles of the fetal heart. There is, however, little correlation between the decrease in shortening fraction and the volume of red cells given at intrauterine transfusion. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.