Placental gross / microscopic abnormalities, nonneoplastic
Placental site subinvolution

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

Revised: 13 October 2017, last major update November 2011

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

PubMed Search: Placental site subinvolution

Cite this page: Ziadie, M. Placental site subinvolution. website. Accessed March 23rd, 2018.
Definition / general
  • Delayed / incomplete sloughing of the modified spiral arteries in the superficial myometrium beneath the placental attachment site
  • Important cause of late postpartum bleeding
  • May be due to deficiency in immunologic factors necessary for normal involution of uteroplacental arteries
Microscopic (histologic) description
  • Curettings show large, dilated vessels that lack a medial coat and are partially / completely thrombosed
  • Trophoblasts may be present