The oxygen tension of the blood in the umbilical cord and the intervillous space

Abstract

The oxygen tension in the umbilical vein at the time of delivery in normal cases ranges from 6 to 46 mm. Hg with a mean of 29·3 mm. Hg. In the umbilical arteries the range is from 6 to 32 mm. Hg with a mean of 18·3 mm. Hg. The mean values in a group of slightly asphyxiated infants in both arteries and vein is a few mm. Hg lower. The mean value in the umbilical vein is the same in the normal group as in a group of infants with meconium stained amniotic fluid, but the mean value in the arteries in this group is about the same as in the asphyxiated group. In the intervillous space the mean PO 2 in 25 cases is 39·9 mm. Hg.