Loss and regeneration of the microvilli of human placental syncytiotrophoblast.

In order to explore the functional role of microvilli of the syncytiotrophoblast of the human full-term placenta, 16 placentas were examined by scanning electron microscopy (SEM). Our results showed that the microvilli projecting from the apical portion of the syncytiotrophoblast appeared to be highly pleomorphic and showed regional variations in their distribution. This has been correlated to the difference in the stage of growth of microvilli following certain obvious examples of loss. Such a process of distortion and renewal or regeneration may suggest a dynamic functional activity of the microvilli on the villous surface.