Placenta
Nonneoplastic placental conditions and abnormalities
Umbilical cord
Single umbilical artery and supernumerary vessels
Author: Mandolin S. Ziadie, M.D.
Last author update: 1 November 2011
Last staff update: 29 October 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Single umbilical artery[title] "loattrfull text"[sb]
Table of Contents
Single umbilical artery | Supernumerary vessels | Gross description | Microscopic (histologic) imagesCite this page: Ziadie MS. Single umbilical artery and supernumerary vessels. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/placentasua.html. Accessed May 30th, 2023.
Single umbilical artery
- Two vessel cord (usually are 3 vessels) with a single artery and a single vein (a hypoplastic artery may be present)
- Remaining artery may be a persistent vitelline artery in cases of caudal regression / synringomelia
- Diagnosed in 1% of placentas, with higher rates occurring with congenital anomalies, perinatal death and fetal growth restriction
- Also more common in maternal diabetes
- No increased risk of postneonatal mortality
Supernumerary vessels
- Four or more umbilical cord vessels due to an extra artery or vein
- May be associated with fetal anomalies and maternal smoking
- Thought to originate from persistent umbilical veins or vitelline vessels
- Looping may cause artifactual supernumerary vessels and should be excluded on gross examination
Gross description
- Evaluation of vessel number should be performed away from the disc due to the possibility of umbilical artery anastamoses / fusion in this location
- Single umbilical artery associated with higher incidence of abnormal cord (velamentous) and membrane (circumvallate) insertion
Microscopic (histologic) images
Images hosted on other servers:
Two vessel umbilical cord
