Placental Apoptosis in Normal Human Pregnancy

Am J Obstet Gynecol. 1997 Jul;177(1):57-65. doi: 10.1016/s0002-9378(97)70438-1.


Objectives: The study aims were to conclusively demonstrate apoptosis in the human placenta and to quantify its incidence at different stages of pregnancy.

Study design: Placental samples were obtained from 28 first-trimester pregnancies and 38 uncomplicated third-trimester pregnancies. Light microscopy, electron microscopy, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate marker nick end-labeling staining were used to identify apoptosis. Light microscopy was used to quantify its incidence.

Results: Apoptosis has been conclusively demonstrated within placental tissue. Quantification of apoptosis (medians and interquartile ranges) was as follows: first trimester (n = 28), 0.07% of cells (0.05% to 0.14%); third trimester (n = 39), 0.14% of cells (0.09% to 0.20%). The incidence of apoptosis was significantly higher in the third trimester than in the first trimester (p < 0.01, Mann-Whitney U test).

Conclusions: Placental apoptosis increases significantly as pregnancy progresses, suggesting that it may play a role in the normal development and aging of the placenta.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Apoptosis / physiology*
  • Cell Nucleus / chemistry
  • Cell Nucleus / ultrastructure
  • DNA / analysis
  • Female
  • Humans
  • Immunohistochemistry
  • Incidence
  • Microscopy, Electron
  • Placenta / chemistry
  • Placenta / physiology*
  • Placenta / ultrastructure*
  • Pregnancy / physiology*
  • Pregnancy Trimester, Second
  • Pregnancy Trimester, Third


  • DNA