[Total estrogen level in umbilical cord blood during physiological labor].

The levels of total oestrogens in umbilical vein and artery and in maternal peripheral blood were investigated in 24 normal labours. The levels in the umbilical artery were significantly lower than in the vein. This difference was connected with the level of oestrogens in umbilical vein, but not with the foetal weight. No correlation between the oestrogens levels in the umbilical and maternal blood was found.