Doppler assessment of the fetal venous system.

This article describes the achievements in Doppler measurements of the fetal venous circulation with emphasis on the clinical impact of these techniques. In rhesus isoimmunization, fetal venous flow assessment gives useful information on the fetal haematologic condition and on the impact of blood transfusion. In first trimester fetuses, Doppler evaluation of the ductus venosus and umbilical vein could attribute to the detection of cardiac defects and/or chromosomal abnormalities. The inferior vena cava flow velocity waveform could be studied in cases of fetal arrhythmias to be able to diagnose the type of fetal heart rhythm disturbances. One of the more important applications of venous Doppler assessment is its use in the evaluation of the intrauterine growth retarded fetus, who is suffering from placental insufficiency. Decrease of the late diastolic flow component in the ductus venosus waveform and the presence of umbilical venous pulsations are distinct alterations, which have been detected before cardiotocogram deterioration occurs. The clinical possibilities of venous Doppler measurements are limited, and the use of the techniques requires intensive training.