[Some experiences concerning the effect of fetal respiratory movement (author's transl)]

The effect of negative pressure by intrauterine respiratory movements of 115 fetal rabbits is examined between the 25th and 28th day of gestation. An intraamnial injection of Burri-ink with particles of the size between 20 and 50 nm and of a suspension of polyamid (size between 25 and 40 micrometer) in physiological NaC1-solution was done. Both markers are not inspirated during the time of 24 h p.i. However you can find them after 19 min in the circulated fetal blood. There is the same effect if you block respiratory movements by drugs. There is a correlation to the concentration of the markers in the amniotic fluid, but no correlation to the size of the particles of those markers.