Circumvallate placenta
Updates to Article Attributes
Circumvallate placenta refers to a variation in placental morphology in which, as a result of a small chorionic plate, the amnion and chorion fetal membranes ‘double back’ around the edge of the placenta.
Epidemiology
The prevalance is estimated to be at around 1-7% 3.
Pathology
There is inward insertion of membranes from the edge towards the center of the placenta (from deep implantation of the placenta into the decidua). Because of this excessive implantation, the placenta covers more than half of the fetal sac. The placenta reduces this excessive covering to the normal one-fourth by separating from the uterine wall, with the resultant back folding of the placenta and fetal membranes towards the chorionic surface.
This can be accompanied by tethering of membranes, frequently often in association with a marginal infarction, haemorrhage, or fibrin deposition.
Radiographic features
Antenatal ultrasound
May show a peripheral rim of chorionic tissue appearing as an echodense ridge (placental shelf) 2,6.
Treatment and prognosis
Recognised complications include 1,4:
- higher incidence of placental abruption
- increased risk of IUGR
Differential diagnosis
For a raised placental edge on ultrasound:
- amniotic shelf (amniotic sheet)
- part of an amniotic band close to the placenta
-<p><strong>Circumvallate placenta</strong> refers to a <a href="/articles/variation-in-placental-morphology">variation in placental morphology</a> in which, as a result of a small chorionic plate, the amnion and chorion fetal membranes ‘double back’ around the edge of the placenta.</p><h4>Epidemiology</h4><p>The prevalance is estimated to be at around 1-7% <sup>3</sup>.</p><h4>Pathology</h4><p>There is inward insertion of membranes from the edge towards the center of the placenta (from deep implantation of the placenta into the decidua). Because of this excessive implantation, the placenta covers more than half of the fetal sac. The placenta reduces this excessive covering to the normal one-fourth by separating from the uterine wall, with the resultant back folding of the placenta and fetal membranes towards the chorionic surface.</p><p>This can be accompanied by tethering of membranes, frequently often in association with a marginal infarction, haemorrhage, or fibrin deposition. </p><h4>Radiographic features</h4><h5>Antenatal ultrasound</h5><p>May show a peripheral rim of chorionic tissue appearing as an echodense ridge (<a href="/articles/placental-shelf">placental shelf</a>) <sup>2,6</sup>.</p><h4>Treatment and prognosis</h4><p>Recognised complications include <sup>1,4</sup></p><ul>- +<p><strong>Circumvallate placenta</strong> refers to a <a href="/articles/variation-in-placental-morphology">variation in placental morphology</a> in which, as a result of a small chorionic plate, the amnion and chorion fetal membranes ‘double back’ around the edge of the placenta.</p><h4>Epidemiology</h4><p>The prevalance is estimated to be at around 1-7% <sup>3</sup>.</p><h4>Pathology</h4><p>There is inward insertion of membranes from the edge towards the center of the placenta (from deep implantation of the placenta into the decidua). Because of this excessive implantation, the placenta covers more than half of the fetal sac. The placenta reduces this excessive covering to the normal one-fourth by separating from the uterine wall, with the resultant back folding of the placenta and fetal membranes towards the chorionic surface.</p><p>This can be accompanied by tethering of membranes, frequently often in association with a marginal infarction, haemorrhage, or fibrin deposition. </p><h4>Radiographic features</h4><h5>Antenatal ultrasound</h5><p>May show a peripheral rim of chorionic tissue appearing as an echodense ridge (<a href="/articles/placental-shelf">placental shelf</a>) <sup>2,6</sup>.</p><h4>Treatment and prognosis</h4><p>Recognised complications include <sup>1,4</sup>:</p><ul>
-</ul><h4>Differential diagnosis</h4><p>For a <strong>raised placental edge on ultrasound:</strong></p><ul>- +</ul><h4>Differential diagnosis</h4><p>For a raised placental edge on ultrasound:</p><ul>
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