Progesterone, 20 alpha-dihydroprogesterone and 20 beta-dihydroprogesterone in mother and child at birth.

In 14 healthy pregnant women at term progesterone (P) and 20 alpha-dihydroprogesterone (20 alpha-DHP) were determined by radioimmunoassay both in the maternal and foetal compartments. The average concentrations were as follows (ng/ml blood or ng/g wet weight tissue): peripheral maternal blood P 56 +/- 26, 20 alpha-DHP 16 +/- 8; placental tissue P 2514 +/- 1516, 20 alpha-DHP 429 +/- 412; placental blood P 365 +/- 160, 20 alpha-DHP 35 +/- 18; blood of the umbilical vein P 388 +/- 121, 20 alpha-DHP 33 +/- 15; blood of the umbilical arteries P 162 +/- 62, 20 alpha-DHP 28 +/- 10. In 5 healthy pregnant women at term progesterone (P), 20 alpha-dihydroprogesterone (20 alpha-DHP) and 20 beta-dihydroprogesterone (20 beta-DHP) were also determined by gas-liquid chromatography both in the maternal and foetal compartments. The average concentrations were as follows (ng/ml plasma or ng/g wet weight tissue): peripheral maternal plasma P 129 +/- 49, 20 alpha-DHP 15 +/- 15, 20 beta-DHP 1.7 +/- 0.9; placental tissue P 5060 +/- 1435, 20 alpha-DHP 230 +/- 158, 20 beta-DHP 38 +/- 30; placental plasma P 723 +/- 245, 20 alpha-DHP 24 +/- 13, 20 beta-DHP 1.0 +/- 0.1; plasma of the umbilical vein P 740 +/- 227, 20 alpha-DHP 17 +/- 3, 20 beta-DHP 1.2 +/- 0.3; plasma of the umbilical arteries P 324 +/- 94, 20 alpha-DHP 17 +/- 5, 20 beta-DHP 2.6 +/- 2.1. These results show that, contrary to the progesterone concentrations, no significant difference exists in the concentrations of 20 alpha-DHP and 20 beta-DHP between the blood from the umbilical vein and arteries. Furthermore, no significant difference could be found in the concentrations of P and 20 alpha-DHP between the sexes in either the blood from the umbilical vein or from the umbilical arteries.