• Decidual cells;
  • pregnancy;
  • pseudopregnancy;
  • bone marrow chimeras

ABSTRACT: Decidual cells are a distinctive cell population observed in the mammalian endometrium during pregnancy. Their appearance can also be induced with appropriate stimuli in the hormone-primed pseudopregnant uterus. This review deals with their life history, including the dynamic morphological events during the process of decidualization, cytochemical markers for decidual cell reaction, the surface markers and functions of decidual cells, and, finally, the origin and fate of this cell class. The recent discovery of the bone marrow origin of decidual cell precursors adds a new dimension to decidual cell biology. Future studies of steps in the differentiation of the decidual cell lineage await the identification of unique lineage-specific cell-surface or cytoplasmic marker(s); a precise knowledge of decidual cell functions can only be obtained from a discriminating analysis using purified cell populations.