Fetal ductus venosus flow assessment
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- updated 11 May 2022:
Nothing to disclose
Updates to Article Attributes
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was changed:
Fetal ductus venosus flow assessment can be useful in a number of situations in fetal ultrasound:
- first-trimester screening for aneuploidic anomalies
- second and third-trimester scanning when there are concerns regarding
Of all the pre-cardiac veins, the ductus venosus allows the most accurate interpretation of fetal cardiac function as well as myocardial haemodynamics 9.
Radiographic assessment
Ultrasound
Technique
- the fetus should be as still as possible
- variability in the heights of the S and D waves may indicate fetal breathing, which is normal, but wait for the fetus to be more still before evaluating
- the probe is ideally
focusedfocussed so sampling is done where the umbilical vein joins the ductus venosus - a right ventral mid-sagittal view of the fetal trunk should be obtained and colour flow mapping used to demonstrate the umbilical vein, ductus venosus and fetal heart
- the probe is ideally angled to allow a mid sagittal plane or a transverse oblique plane through the fetal abdomen
- the image should be magnified enough for the fetal thorax and abdomen to occupy the whole screen
- do not contaminate the ductus venosus flow with the flow from the fetal inferior vena cava, for this the Doppler sample should be small (0.5-1 mm)
- the insonation angle should be 30° or less
- the sweep speed should be high (2-3 cm/s) so that the waveforms are spread allowing better assessment of the A wave
- set the wall filter low enough so that the A wave is not obscured 10
On Doppler ultrasound, the flow in the ductus venosus has a characteristic triphasic waveform where in a normal physiological situation flow should always be in the forward direction 7 (i.e. towards the fetal heart).
This triphasic waveform comprises of:
- S wave: corresponds to fetal ventricular systolic contraction and is the highest peak
- D wave: corresponds to fetal early ventricular diastole and is the second highest peak
-
A wave: corresponds to fetal atrial contraction and is the lowest point in the wave form albeit still being in the forward direction
- as above, reversal of the A wave (i.e. crossing the baseline) is always abnormal 10
See also
-<p><strong>Fetal ductus venosus flow assessment </strong>can be useful in a number of situations in fetal ultrasound:</p><ul>-<li>first-trimester screening for <a href="/articles/aneuploidic-anomalies">aneuploidic anomalies</a>-</li>-<li>second and third-trimester scanning when there are concerns regarding<ul>-<li><a href="/articles/intrauterine-growth-restriction">intrauterine growth restriction (IUGR)</a></li>-<li><a href="/articles/fetal-cardiac-compromise">fetal cardiac compromise</a></li>-</ul>-</li>-</ul><p>Of all the pre-cardiac veins, the <a href="/articles/ductus-venosus">ductus </a><a href="/articles/ductus-venosus">venosus</a> allows the most accurate interpretation of fetal cardiac function as well as myocardial haemodynamics <sup>9</sup>.</p><h4>Radiographic assessment</h4><h5>Ultrasound</h5><h6>Technique</h6><ul>-<li>the fetus should be as still as possible<ul><li>variability in the heights of the S and D waves may indicate fetal breathing, which is normal, but wait for the fetus to be more still before evaluating</li></ul>-</li>-<li>the probe is ideally focused so sampling is done where the <a href="/articles/umbilical-vein">umbilical vein</a> joins the <a href="/articles/ductus-venosus">ductus venosus</a>-</li>-<li>a right ventral mid-sagittal view of the fetal trunk should be obtained and colour flow mapping used to demonstrate the umbilical vein, ductus venosus and fetal heart</li>-<li>the probe is ideally angled to allow a mid sagittal plane or a transverse oblique plane through the fetal abdomen</li>-<li>the image should be magnified enough for the fetal thorax and abdomen to occupy the whole screen</li>-<li>do not contaminate the ductus venosus flow with the flow from the fetal <a href="/articles/inferior-vena-cava-1">inferior vena cava</a>, for this the Doppler sample should be small (0.5-1 mm)</li>-<li>the insonation angle should be 30° or less</li>-<li>the sweep speed should be high (2-3 cm/s) so that the waveforms are spread allowing better assessment of the A wave </li>-<li>set the wall filter low enough so that the A wave is not obscured <sup>10</sup>-</li>-</ul><p>On Doppler ultrasound, the flow in the ductus venosus has a characteristic <strong>triphasic</strong> waveform where in a <strong>normal physiological situation</strong> flow should always be in the forward direction <sup>7</sup> (i.e. towards the fetal heart).</p><p>This triphasic waveform comprises of:</p><ul>-<li>-<strong>S wave:</strong> corresponds to fetal ventricular systolic contraction and is the highest peak</li>-<li>-<strong>D wave:</strong> corresponds to fetal early ventricular diastole and is the second highest peak</li>-<li>-<strong>A wave:</strong> corresponds to fetal atrial contraction and is the lowest point in the wave form albeit still being in the forward direction<ul><li>as above, reversal of the A wave (i.e. crossing the baseline) is always abnormal <sup>10</sup>-</li></ul>-</li>- +<p><strong>Fetal ductus venosus flow assessment </strong>can be useful in a number of situations in fetal ultrasound:</p><ul>
- +<li>first-trimester screening for <a href="/articles/aneuploidic-anomalies">aneuploidic anomalies</a>
- +</li>
- +<li>second and third-trimester scanning when there are concerns regarding<ul>
- +<li><a href="/articles/intrauterine-growth-restriction">intrauterine growth restriction (IUGR)</a></li>
- +<li><a href="/articles/fetal-cardiac-compromise">fetal cardiac compromise</a></li>
- +</ul>
- +</li>
- +</ul><p>Of all the pre-cardiac veins, the <a href="/articles/ductus-venosus">ductus </a><a href="/articles/ductus-venosus">venosus</a> allows the most accurate interpretation of fetal cardiac function as well as myocardial haemodynamics <sup>9</sup>.</p><h4>Radiographic assessment</h4><h5>Ultrasound</h5><h6>Technique</h6><ul>
- +<li>the fetus should be as still as possible<ul><li>variability in the heights of the S and D waves may indicate fetal breathing, which is normal, but wait for the fetus to be more still before evaluating</li></ul>
- +</li>
- +<li>the probe is ideally focussed so sampling is done where the <a href="/articles/umbilical-vein">umbilical vein</a> joins the <a href="/articles/ductus-venosus">ductus venosus</a>
- +</li>
- +<li>a right ventral mid-sagittal view of the fetal trunk should be obtained and colour flow mapping used to demonstrate the umbilical vein, ductus venosus and fetal heart</li>
- +<li>the probe is ideally angled to allow a mid sagittal plane or a transverse oblique plane through the fetal abdomen</li>
- +<li>the image should be magnified enough for the fetal thorax and abdomen to occupy the whole screen</li>
- +<li>do not contaminate the ductus venosus flow with the flow from the fetal <a href="/articles/inferior-vena-cava-1">inferior vena cava</a>, for this the Doppler sample should be small (0.5-1 mm)</li>
- +<li>the insonation angle should be 30° or less</li>
- +<li>the sweep speed should be high (2-3 cm/s) so that the waveforms are spread allowing better assessment of the A wave </li>
- +<li>set the wall filter low enough so that the A wave is not obscured <sup>10</sup>
- +</li>
- +</ul><p>On Doppler ultrasound, the flow in the ductus venosus has a characteristic <strong>triphasic</strong> waveform where in a <strong>normal physiological situation</strong> flow should always be in the forward direction <sup>7</sup> (i.e. towards the fetal heart).</p><p>This triphasic waveform comprises of:</p><ul>
- +<li>
- +<strong>S wave:</strong> corresponds to fetal ventricular systolic contraction and is the highest peak</li>
- +<li>
- +<strong>D wave:</strong> corresponds to fetal early ventricular diastole and is the second highest peak</li>
- +<li>
- +<strong>A wave:</strong> corresponds to fetal atrial contraction and is the lowest point in the wave form albeit still being in the forward direction<ul><li>as above, reversal of the A wave (i.e. crossing the baseline) is always abnormal <sup>10</sup>
- +</li></ul>
- +</li>
References changed:
- 5. Barry B. Goldberg, John P. McGahan. Atlas of Ultrasound Measurements. (2006) ISBN: 032303229X - <a href="http://books.google.com/books?vid=ISBN032303229X">Google Books</a>
- 7. Werner O. Schmidt, Asim Kurjak. Color Doppler Sonography in Gynecology and Obstetrics. (2004) ISBN: 9781588902566 - <a href="http://books.google.com/books?vid=ISBN9781588902566">Google Books</a>
- 8. Julia A. Drose. Fetal Echocardiography. (2010) ISBN: 9781416056690 - <a href="http://books.google.com/books?vid=ISBN9781416056690">Google Books</a>
- 9. Eberhard Merz. Ultrasound in Obstetrics and Gynecology. (2005) ISBN: 9781588901477 - <a href="http://books.google.com/books?vid=ISBN9781588901477">Google Books</a>
- 5. McGahan, John P.. Atlas of Ultrasound Measurements. (2006) ISBN: 032303229X
- 7. Werner O. Schmidt, Asim Kurjak. Color Doppler Sonography in Gynecology and Obstetrics. (2004) ISBN: 1588902560
- 8. Drose, Julia A.. Fetal Echocardiography. (2010) ISBN: 9781416056690
- 9. F. Bahlmann (Contributor), R. Bollmann (Contributor), R. Chaoui (Contributor). Ultrasound in Obstetrics and GynecologyDiagnostic Ultrasound in Obstetrics: Obstetrics. (2005) ISBN: 1588901475
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