The ductus venosus is a small but important vessel in fetal circulation that channels a portion of the oxygen-rich blood from the umbilical vein directly through the liver to the inferior vena cava and then to the heart, bypassing the liver’s capillary network. Doppler evaluation of the ductus venosus has become an important part of first trimester screening for chromosomal abnormalities and heart defects. A normal ductus venosus waveform shows forward flow throughout the cardiac cycle, while reversed flow during atrial contraction is an abnormal finding associated with increased risk of chromosomal anomalies and congenital heart disease. After birth, the ductus venosus closes and becomes the ligamentum venosum.
Sonography Term