[Effects of uterine contraction and a beta-stimulant on placental and fetal brain blood flow in correlation with fetal heart rate changes].

The effects of uterine contraction on placental and fetal brain blood flow in correlation with fetal heart rate change and also beta-stimulant on placental and fetal brain blood flow during late deceleration were studied in late pregnant rabbits. We determined the fetal heart rate (FHR) and placental and fetal brain blood flow by a thermocouple method under urethane anesthesia. Fetuses exposed to a more than 30% decrease in placental blood flow by uterine contraction developed more than 20% bradycardia and also a significant decrease in fetal brain blood flow. There are a significant relationship between the decrease in FHR and fetal brain blood flow. beta-stimulant administered to the mother suffering from already severely hypoxic fetal bradycardia increased FHR in accordance with the increase in the placental blood flow and moreover there was recovery from decreased fetal brain blood flow.