Placenta
Gross / macroscopic variations and conditions
Umbilical cord
Marginal insertion
Author: Paul J. Kowalski, M.D.
Last author update: 1 November 2015
Last staff update: 28 October 2020
Copyright: 2002-2025, PathologyOutlines.com, Inc.
PubMed Search: Marginal insertion umbilical cord
Table of Contents
Definition / general | Terminology | Epidemiology | Etiology | Clinical features | Case reports | Gross description | Gross images | Microscopic (histologic) descriptionCite this page: Kowalski PJ. Marginal insertion. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/placentamarginalinsert.html. Accessed January 3rd, 2025.
Definition / general
- Generally refers to an umbilical cord insertion site located at or near the disc margin
Terminology
- When directly at the disc margin (on the height or thickness dimensional aspect), the insertion is described as marginal or "battledore" (resembling a badminton racket)
- When near the disc margin (on the width dimensional aspect), the insertion is described as peripheral or eccentric
Epidemiology
- Marginal insertions occur in approximately 8% of singleton gestations
- Occur in 20 - 30% of twin pregnancies, with higher incidences in monochorionic twins
Etiology
- Developing placental disc demonstrates migrational tropism towards the uterine vascular supply
- When the uterine vascular supply is asymmetric, the disc will migrate in relation to the relatively stationary umbilical cord, resulting in a cord insertion site that is no longer centrally located
- Competition among twins for the uterine vascular supply can also result in asymmetric placental development and a marginally or peripherally located umbilical cord
Clinical features
- Fetal growth restriction and the presence of a single umbilical artery (two vessel umbilical cord) are slightly increased with marginal insertions
- Major chorionic vessels (that would normally insert on the disc more centrally) can instead transverse the adjacent membranes, are termed aberrant membrane vessels and are at risk for rupture
- Marginal vessels are more likely to undergo twisting, occlusion or thrombosis
- Discordant growth or fetal growth restriction may be seen with affected twin pregnancies
Case reports
- Monochorionic, monoamniotic, double battledore placenta with stillbirth (Am J Obstet Gynecol 1977;128:697)
- Velamentous / marginal cord insertion (Am J Obstet Gynecol 2013;208:S79)
Gross description
- Umbilical cord insertion will occur at or near the disc margin
- Aberrant membrane vessels may be present and may show evidence of rupture, hemorrhage or thrombosis
Gross images
Images hosted on other servers:
Marginal "battledore" insertion
Marginal insertion
Various images
Microscopic (histologic) description
- Hemosiderin laden macrophages may be seen in the membranes or adjacent to vessels that have undergone rupture or thrombosis
