[Significance of the measurement of placental perfusion by radionuclides in prenatal diagnosis in pregnancies at risk].

The evaluation of placental perfusion measurements in 102 high-risk pregnancies from the 28th to 41st gestational week is described. --Following an injection of In113m-chloride, the half-life value of the rise in activity was determined by computer evaluation according to a single-compartment model. --Mean value of the half-life value of the rise of the placental perfusion curve is 12.55 +/- 2.42 seconds (33 normal test persons). --A half-life value of 20.62 +/- 2.43 seconds was determined in high-risk pregnancies. --In cases of EPH-gestosis a half-life value of 22.55 +/- 3.64 seconds was determined. Individual cases showed values of 50 seconds for gestosis. There was no correlation between the half-life value and the size of the placenta and or gestational age.