[Significance of model studies for explanation of the pathogenesis of the mechanically induced birth trauma (author's transl)].

We have studied the propotions of displacements from fetal cerebral parts during simulated intrauterine pressure. Stillborn children from the death to the experiments last only some hours, were put in cephalic position in our birth model. The cavum uteri was simulated by a metal cylinder, in which we gave compressed air for simulating the labor. The pressure was held about 100 mm Hg. A rubber cuff was fixed on the metal cylinder and let an opening of 8 cm, simulating the cervix uteri. The model with the death infant in it was frozen and than the fetal head sectioned in slides of 1,5 cm in the right of the birth pressure axis. We found, that the gyri occipital were widened, opposite the gyri frontal were compressed. Parieto-occipital we found a venous blood congestion. The brain stem was kinked and displaced dorsal. In one case we carried out in the meantime an aniogram. The cerebral vessels became under the pressure elongated. This was reversible by decrease of the pressure. The limitation of such model studies are give in some facts. We do not know, how much the loosening of the skull, following the fetal death, leads to a more than normal shifting. We further do not know, which proportions of the displacements of the cerebral substance during labor from the fetus could be compensated. Our findings suggest, that it is possible, that cerebral blood flow will be altered by displacements of the cerebral masses during intrauterine pressure. But we have not exact informations about it.