[Morphology of the rat placenta in experimental, hormone-induced, prolonged pregnancy. II. Plancenta in intrauterine macerated dead rat fetuses].

In course of overdue pregnancy in rats, produced by application of synthetic gestagens the intrauterine death rate rises, when the gestation time is more than 23 days. Placentas of 47 macereted fetus rats we have investigated. The pathologic-anatomical picture of the placenta characterized by collaps and following regression of the peripheral fetal blood system. Furthermore, there are narrowing processes in great fetal vessels. In the maternal sinus occurs fibrin. The labyrinth of the placenta inclines by production of collagen fibers to a homogenous structure. The trophoblastic epithel is less differentiated. These findings in rat placentas we have compared with those in human placentas in cases of fetal maceration. The worth of these changes for differentiation of intravital against postmortal regressive processes is evident.