Maternoembryonic transfusion and congenital malformations: an experimental study using rat embryos.

In an experimental study, using an in vitro whole rat embryo culture, the effects of a maternoembryonic transfusion and immunologic interaction on the development of ten-day-old rat embryos (stages 8 to 10 somites) has been studied. Transplacental transfusion has been simulated by embryonic intracardiac microinjection of 0.1 to 0.5 microL immunologically active rat serum. After an incubation of 24 and 48 hours, respectively, the embryos were killed. All tested embryos have survived the incubation period. On microscopic examination of the tested embryos those that were taken from the incubator after 24 hours showed no signs of pathogenic cell degeneration, while the embryos that were taken from the incubator after 48 hours all had localized lesions with pathogenic cell degeneration in one or multiple major structures. The neurectoderm and endoderm seem to be the most sensitive tissues in this period of organogenesis. The results suggest that immunologic reaction to transplacental transfusion of maternal serum may lead to congenital malformations.