Uterine activity following intravenous administration of oxytocin to the foetal Sheep

CONCENTRATIONS of oxytocin in umbilical cord blood are high in the newborn human¹ and in several species the foetal pituitary contains large amounts of oxytocin and neural lobe hormone carrier proteins, the neurophysins^2,3. If the foetal posterior pituitary is to play a part in labour, however, it must not only secrete oxytocin but this oxytocin must pass from the foetal vasculature to the myometrial cell. No observations have been reported regarding the ability of oxytocin to produce uterine contractions when administered from the foetal side of the placenta.