ABSTRACT
Using a variety of experimental techniques, including perfusion of placentas in situ, injection into the intact foeto-placental unit via the umbilical vein, as well as long-term administration into the amniotic sac or antecubital vein of the mother, very little if any oestrone, 17β-oestradiol- or oestriol-like radioactive material could be detected in the placenta, foetal tissues and urine of the mother following the administration of labelled progesterone.
The results are interpreted as supporting the concept that progesterone is not a significant precursor of placental oestrogens.
