Involution of Implantation Site and Retained Placenta

  • Kurt Benirschke
  • Peter Kaufmann


Pathologists rarely obtain a postpartum uterus for a detailed study of the involutional changes that take place at the former site of implantation. Therefore involution of the normal placental site has been studied by only a few investigators. Normally, the postpartum lochia contain the decidual remnants, including perhaps the remains of the vasculature that had previously undergone the so-called physiological changes of pregnancy. Only when significant postpartum hemorrhage occurs and hysterectomy becomes necessary is the pathologist asked to seek the cause of the bleeding. He or she may then find remains of villi, incompletely thrombosed vessels, “placental polyps,” and some degree of inflammatory reaction. These areas are difficult to study objectively because most pathologists have no experience with the normal, complex process of placental site involution. Williams (1931), in a classical paper, attempted to rectify this situation. His study should be read before any interpretation of such postpartum uteri is undertaken. It must also be recognized that in 85% of normal, delivered placentas the decidua basalis shows foci of polymorphonuclear leukocyte infiltration (Schneider, 1970). These cells are part of an apparently normal process of implantation and are not considered an expression of deciduitis or infection.


Placental Tissue Implantation Site Placenta Accretas Placental Site Stromal Fibrosis 


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  1. Anderson, W.R., and Davis, J.: Placental site involution. Am. J. Obstet. Gynecol. 102: 23–33, 1968.PubMedGoogle Scholar
  2. Bronson, R., Volk, T.L., and Ruebner, B.H.: Involution of placental site and corpus luteum in the monkey. Am. J. Obstet. Gynecol. 113: 70–75, 1972.PubMedGoogle Scholar
  3. Dyer, I., and Bradburn, D.M.: An inquiry into the etiology of placental polyps. Am. J. Obstet. Gynecol. 109: 858–867, 1971.PubMedGoogle Scholar
  4. Fox, H.: Morphological changes in the human placenta following fetal death. J. Obstet. Gynaecol. Br. Commonw. 75: 839–843, 1968.PubMedCrossRefGoogle Scholar
  5. Friedländer, C.: Physiologisch-anatomische Untersuchungen über den Uterus. Simmel, Leipzig, 1870.Google Scholar
  6. Hoberman, L.K., Hawkinson, J.A., and Beecham, C.T.: Placental polyp: report of 3 cases. Obstet. Gynecol. 22: 25–29, 1963.PubMedGoogle Scholar
  7. Khong, T.Y., and Khong, T.K.: Delayed postpartum hemorrhage: a morphologic study of causes and their relation to other pregnancy disorders. Obstet. Gynecol. 82: 17–22, 1993.PubMedGoogle Scholar
  8. Lanman, J.T., Mitsudo, S.M., Brinson, A.O., and Thau, R.B.: Fetectomy in monkeys (Macaca mulatta); retention of the placenta past term. Biol. Reprod. 12: 522–525, 1975.PubMedCrossRefGoogle Scholar
  9. Lawrence, W.D., Qureshi, F., and Bonakdar, M.I.: “Placental polyp”: light microscopic and immunohistochemical observations. Hum. Pathol. 19: 1467–1470, 1988.PubMedCrossRefGoogle Scholar
  10. Lewis, J., and Hertz, R.: Effects of early embryectomy and hormonal therapy on the fate of the placenta in pregnant rhesus monkeys. Proc. Soc. Exp. Biol. Med. 123: 805–809, 1966.PubMedGoogle Scholar
  11. Ludwig, H.: Surface structure of the human term placenta and of the uterine wall post partum in the screen scan electron microscope. Am. J. Obstet. Gynecol. 111: 328–344, 1971.PubMedGoogle Scholar
  12. Ludwig, H., and Metzger, H.: Das uterine Placentarbett post partum im Rasterelektronenmikroskop, zugleich ein Beitrag der extravasalen Fibrinbildung. Arch. Gynecol. 210: 251–266, 1971.Google Scholar
  13. Maher, J.A.: Morphologic and histochemical changes in postpartum uterine blood vessels. Arch. Pathol. 67: 175–180, 1959.Google Scholar
  14. Mukaida, T., Yoshida, K., and Soma, H.: A surface ultra-structural study of the placental separation site. J. Clin. Electron Microsc. 8: 5–6, 1975.Google Scholar
  15. Myers, R.E., and Panigel, M.: Experimental placental detachment in the rhesus monkey: changes in villous ultra-structure. J. Med. Primatol. 2: 170–189, 1973.PubMedGoogle Scholar
  16. Nathanielsz, P.W., Figueroa, J.P., and Honnebier, M.B.O.M.: In the rhesus monkey placental retention after fetectomy at 121 to 130 days’ gestation outlasts the normal duration of pregnancy. Am. J. Obstet. Gynecol. 166: 1529–1535, 1992.PubMedGoogle Scholar
  17. Panigel, M., and Myers, R.E.: Histological and ultrastructural changes in rhesus monkey placenta following interruption of fetal placental circulation by fetectomy or interplacental umbilical vessel ligation. Acta Anat. (Basel) 81: 481–506, 1972.Google Scholar
  18. Philippe, E., Ritter, J., Renaud, R., Dellenbach, P., FonckCussac, Y., and Gandar, R.: Les métrorrhagies tardives du post-partum par anomalie d’involution des artères utéroplacentaires. Rev. Fr. Gynecol. 63: 255–262, 1968.Google Scholar
  19. Rutherford, R.N., and Hertig, A.T.: Noninvolution of the placental site. Am. J. Obstet. Gynecol. 49: 378–384, 1945.Google Scholar
  20. Schneider, L.: Über Vorkommen und Bedeutung leukocytärer Infiltrate im Ablösungsbereich der spontan geborenen Placenta. Arch. Gynecol. 208: 247–254, 1970.Google Scholar
  21. Sharman, A.: Post-partum regeneration of the human endometrium. J. Anat. 87: 1–10, 1953.PubMedGoogle Scholar
  22. Stamm, H.: Alte und neue Probleme bei Plazentarpolypen. Gynaecologia 151: 252–260, 1961.Google Scholar
  23. Thorsteinsson, V.T., and Kempers, R.D.: Delayed postpartum bleeding. Am. J. Obstet. Gynecol. 107: 565–571, 1970.PubMedGoogle Scholar
  24. Van Wagenen, G., and Newton, W.H.: Pregnancy in the monkey after removal of the fétus. Surg. Gynecol. Obstet. 77: 539–549, 1943.Google Scholar
  25. Walsh, S.Z.: Maternal effects of early and late clamping of the umbilical cord. Lancet 1: 996–997, 1968.PubMedCrossRefGoogle Scholar
  26. Williams, J.W.: Regeneration of the uterine mucosa after delivery, with especial reference to the placental site. Am. J. Obstet. Gynecol. 22:664–696, 793–796, 1931.Google Scholar
  27. Young, R.H., Kurman, R.J., and Scully, R.E.: Placental site nodule. Mod. Pathol. 1: 107A, 1988.Google Scholar

Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • Kurt Benirschke
    • 1
  • Peter Kaufmann
    • 2
  1. 1.University Medical CenterUniversity of California, San DiegoSan DiegoUSA
  2. 2.Institut für Anatomie der Medizinischen FakultätRheinisch-Westfälische Technische Hochschule AachenAachenGermany

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