Venous Doppler in the assessment of fetal cardiovascular status

Purpose of review: The purpose of this review is to highlight recent developments in the Doppler assessment of the fetal venous circulation with special reference to clinical applications in the human fetus. Recent findings: Doppler evaluation of the fetal venous circulation has increased our understanding of fetal cardiovascular function. Examples include the regulatory role of the ductus venosus in fetal nutrient partitioning and the significance of venous and arterial circulatory watershed areas. Alterations in cardiac afterload, contractility compliance, intravascular volume status and heart rate modulate venous and arterial flow velocity waveforms. Concurrent examination of these cardiovascular factors is of great importance in fetal growth restriction, complicated monochorionic multiple gestation, fetal hydrops and arrhythmia. In these conditions, comprehensive Doppler assessment provides critical diagnostic and prognostic information and has a key role in directing interventions. Summary: Venous Doppler has added a critical dimension to the understanding of fetal cardiovascular pathophysiology. In both health and disease, venous Doppler must now occupy a fundamental position in the comprehensive assessment of the fetal circulation.