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Difference between revisions of "Placenta"
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→Cord pathology: more
(→Twin placentas: +cord abn.) |
(→Cord pathology: more) |
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*[http://www.glowm.com/resources/glowm/graphics/figures/v2/1070/05b.jpg SUA (glown.com)].<ref>URL: [http://www.glowm.com/?p=glowm.cml/section_view&articleid=151 http://www.glowm.com/?p=glowm.cml/section_view&articleid=151]. Accessed on: 8 January 2011.</ref> | *[http://www.glowm.com/resources/glowm/graphics/figures/v2/1070/05b.jpg SUA (glown.com)].<ref>URL: [http://www.glowm.com/?p=glowm.cml/section_view&articleid=151 http://www.glowm.com/?p=glowm.cml/section_view&articleid=151]. Accessed on: 8 January 2011.</ref> | ||
==Insertion== | |||
===Marginal insertion=== | |||
Definition: | |||
*The umbilical cord is attached to the placental disc at its margin. | |||
Prevalence: | |||
*Approximately 12% of placentas.<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref> | |||
Relevance: | |||
*None according to WMSP.<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref> | |||
**In theory, the cord, dependent on its relation to the internal os, is at greater risk of injury (leading to vasa previa) and compression (fetal hypoxia). A retrospective study found cord position in relation to the internal os is predictive for vasa previa.<ref name=pmid20872421>{{cite journal |author=Hasegawa J, Farina A, Nakamura M, ''et al.'' |title=Analysis of the ultrasonographic findings predictive of vasa previa |journal=Prenat. Diagn. |volume=30 |issue=12-13 |pages=1121–5 |year=2010 |month=December |pmid=20872421 |doi=10.1002/pd.2618 |url=}}</ref> | |||
===Velamentous insertion== | |||
Definition: | |||
*The umbilical cord inserts into the fetal membranes.<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref> | |||
**The vessels are ''not'' protected by Wharton's jelly. | |||
***Wharton's jelly = the connective tissue surrounding the vessels in the cord. | |||
Details:<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref> | |||
*3/4 of the time the vessel also branch; in the remaining 1/4 the vessels stay together. | |||
Relevance: | |||
*Increased risk of vasa previa.<ref name=pmid20872421>{{cite journal |author=Hasegawa J, Farina A, Nakamura M, ''et al.'' |title=Analysis of the ultrasonographic findings predictive of vasa previa |journal=Prenat. Diagn. |volume=30 |issue=12-13 |pages=1121–5 |year=2010 |month=December |pmid=20872421 |doi=10.1002/pd.2618 |url=}}</ref> | |||
=Twin placentas= | =Twin placentas= | ||