Placental gross / microscopic abnormalities, nonneoplastic
Increased perivillous fibrin

Author: Mandolin Ziadie, M.D. (see Authors page)

Revised: 12 October 2017, last major update October 2011

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Increased perivillous fibrin

Cite this page: Ziadie, M. Increased perivillous fibrin. website. Accessed November 18th, 2018.
Definition / general
  • Small amounts of fibrin are commonly scattered throughout the normal placenta
  • Diffusely increased amounts of perivillous fibrin involving stem and terminal villi and large enough to be grossly visible are a significant pathologic finding
  • Increased fibrin may impair gas exchange and lead to growth restriction, oligohydramnious, premature birth (Arch Pathol Lab Med 1994;118:698), neurologic impairment or fetal death
Gross description
  • Strands of pale, firm parenchyma
Microscopic (histologic) description
  • Abundant perivillous fibrin that obliterates the intervillous space with loss of the syncytiotrophoblast
  • Requires at least one area of full thickness involvement / entrapment of at least half of the villi on a single slide