In the present study, the volume of villous surface
fibrin decreased in PP group compared to the
C group. Minor perivillous fibrin deposition is
almost always present in term placentas (21). Villous
surface fibrin deposit is derived from the maternal
blood in the intervillous space and an immunological
basis for the activation of this process
has been proposed. The turbulence of maternal
blood within the intervillous space results in
maternal platelet adherence to the villous syncytiotrophoblast
with subsequent thrombosis. The
areas of syncytiotrophoblast covered with fibrin
deposits are cut off from their oxygen supply and
thus undergo ischemic necrosis (22)