Placenta
Placental findings in specific newborn / fetal or maternal conditions
Spontaneous abortion

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

Revised: 16 October 2017, last major update November 2011

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

PubMed Search: Spontaneous abortion[title] placenta

Cite this page: Ziadie, M. Spontaneous abortion. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/placentaspontaneousab.html. Accessed December 15th, 2017.
Definition / general
  • Naturally occurring intrauterine loss is observed in 10 - 15% of clinically recognized pregnancies and 22% of pregnancies detected via hCG levels
  • May be due to fetal factors (e.g. genetic abnormalities) or maternal factors (e.g. anatomic, infectious or autoimmune)
  • Fetal loss with normal karyotype is associated with maternal age < 20 years, chronic intervillositis, increased perivillous fibrin deposition with intermediate trophoblast and decidual plasma cells (Hum Pathol 1999;30:93)
  • Fetal loss with abnormal karyotype is associated with developmental stage < 6 weeks, hydropic villi > 1 mm and villi with 2+ dysmorphic features
Treatment
  • D&C to remove residual trophoblastic tissue to confirm intrauterine pregnancy and rule out gestational trophoblastic disease
  • To diagnose intrauterine pregnancy with certainty, should see fetal parts, villi and trophoblasts in sections of intrauterine contents
  • Enlarged hyalinized spiral arteries and fibrinoid matrix are suggestive
  • Decidual reaction, gestational hyperplasia (glandular secretion, stromal edema) and Arias-Stella reaction are suggestive of pregnancy (not necessarily intrauterine) but are nonspecific (also occur with hormones)
Gross description
  • Soft hemorrhagic mass of spongy tissue (villi) and soft tissue (decidua) that may be attached to membranes as an intact or ruptured gestational sac
  • Report should indicate presence of sac, state of rupture and presence of umbilical cord
  • Fetal parts should be documented and closely examined for anomalies
  • Cytogenetics should be obtained in cases of recurrent spontaneous abortion or malformed fetuses
Microscopic (histologic) description
  • Early abortions show decidual necrosis and decidual blood vessel thrombi, neutrophilic infiltrate, old / recent hemorrhage and edematous avascular villi
  • Dysmorphic villi and villous trophoblastic hyperplasia are suggestive of an abnormal karyotype (Mod Pathol 1998;11:762)
  • Second trimester abortions show focal decidual necrosis, intradecidual hemorrhage, congestion / thrombosis of maternal vessels and avascular villi
Differential diagnosis