Ductus venosus

Full Definition

The ductus venosus is a crucial fetal blood vessel that connects the umbilical vein to the inferior vena cava, allowing oxygenated blood from the placenta to bypass the fetal liver and flow directly to the heart. Doppler assessment of ductus venosus flow is used in first-trimester screening for chromosomal abnormalities and in monitoring fetal well-being in high-risk pregnancies. Abnormal flow patterns, particularly absent or reversed flow during atrial contraction, may indicate fetal heart failure or chromosomal anomalies.

Usage

Usage note: Specify the phase of cardiac cycle when documenting abnormal flow patterns.

In Context

• "Ductus venosus Doppler shows normal forward flow throughout the cardiac cycle." — First trimester screening report
• "Reversed a-wave in the ductus venosus suggests increased risk for trisomy 21." — Genetic counseling documentation