Preload index of the inferior vena cava as a possible predictive marker of hydropic changes in fetuses with Ebstein anomaly

Objective. We aimed to investigate whether the preload index of the inferior vena cava (PLI-IVC) is of diagnostic value in predicting hydropic changes in fetuses with Ebstein anomaly. Methods. Five cases of prenatally diagnosed Ebstein anomaly, which were managed at our institution between 1999 and 2008, were retrospectively reviewed. The PLI-IVC was calculated as the ratio between the reversed flow velocity from the right atrium and the forward velocity of the IVC. Results. The PLI-IVC was high in all the cases. In 2 cases, PLI-IVC values tended to increase gradually before hydropic changes were recognized. In the cases without hydrops, PLI-IVC values exhibited a nonlinear trend throughout gestation and did not show any apparent increase. Conclusions. The upward trend of the PLI-IVC rather than the maintenance of a high value can be considered a sign of cardiac failure. The blood flow pattern in the IVC should be carefully monitored in fetuses with Ebstein anomaly for the early identification of fetal impairment.