Related Experiment Video
Updated: Jul 18, 2026
14:19
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Longitudinal reference ranges for ductus venosus flow velocities and waveform indices
J Kessler1, S Rasmussen, M Hanson
1Department of Clinical Medicine, Section of Obstetrics and Gynaecology, University of Bergen, Bergen, Norway. jorg.kessler@kk.uib.no
Summary
This study establishes new longitudinal reference ranges for fetal ductus venosus Doppler measurements. These updated ranges improve monitoring of fetuses at risk of hemodynamic compromise during pregnancy.
Area of Science:
- Fetal Medicine
- Cardiovascular Physiology
- Medical Imaging Ultrasound
Background:
- Serial Doppler measurements of the ductus venosus are crucial for monitoring fetuses experiencing hemodynamic compromise.
- Existing reference ranges are derived from cross-sectional studies, limiting their utility for serial assessments.
Purpose of the Study:
- To establish longitudinal reference ranges for ductus venosus flow velocities and waveform indices.
- To provide terms for calculating conditional reference ranges for serial fetal monitoring.
Main Methods:
- A longitudinal study involving 160 low-risk pregnancies.
- Pulsed Doppler ultrasound was employed to record ductus venosus blood flow velocities at 4-week intervals from 20-22 weeks of gestation.
Main Results:
- 547 measurements from 160 pregnancies were used to create reference ranges.
- Key velocities (time-averaged maximum, peak systolic, end-diastolic) and the pulsatility index for veins showed distinct developmental trends throughout gestation.
- Conditional reference ranges, based on prior measurements, were found to be narrower and shifted compared to population-wide ranges.
Conclusions:
- The developed longitudinal reference ranges accurately reflect the developmental changes in ductus venosus flow velocities and indices.
- These ranges are suitable for serial fetal monitoring, especially when incorporating conditional terms for enhanced precision.
Related Concept Videos
01:29Blood Flow
Blood is pumped by the heart into the aorta, the largest artery in the body, and then into increasingly smaller arteries, arterioles, and capillaries. The velocity of blood flow decreases with increased cross-sectional blood vessel area. As blood returns to the heart through venules and veins, its velocity increases. The movement of blood is encouraged by smooth muscle in the vessel walls, the movement of skeletal muscle surrounding the vessels, and one-way valves that prevent backflow.
01:19Urodynamic Studies: Uroflowmetry
Uroflowmetry is a non-invasive urodynamic test designed to measure various aspects of urination, including volume, flow rate, and the time to void. This test is crucial for diagnosing and assessing conditions such as bladder outlet obstruction, bladder dysfunction, incomplete bladder emptying, incontinence, and urinary tract blockages caused by benign prostatic hyperplasia (BPH) and urethral strictures.Pre-Test Instructions:Before a uroflowmetry test, patients are typically advised to drink...