An ultrastructural study of the reversibility of the effects of hypoxia on human trophoblast maintained in organ culture.

Ultrastructural changes in normal human trophoblast maintained in hypoxic organ culture are described. Marked structural changes were noted even after hypoxia for 6 hr. These changes could be partly reversed by reoxygenation after hypoxia for 18 hr or less, but no regeneration occurred when hypoxia lasted for 24 hr or longer. The significance of the vulnerability of trophoblast to hypoxia is discussed.