Progesterone 20 alpha-dihydroprogesterone and 20 beta-dihydroprogesterone levels in different compartments from the human foeto-placental unit.

The endogenous levels of progesterone, 20 alpha-dihydroprogesterone and 20 beta-dihydroprogesterone in different foetal tissues, in placental tissue and in foetal blood during pregnancy (week 9-25) were determined by gas-liquid chromatography or by radioimmunoassay. The identification of these steroids in foetal tissues was based on the behaviour in paper and thin-layer chromatography, the formation of different derivatives, and the retention times in gas-liquid chromatography. For additional identification of progesterone and 20 alpha-dihydroprogesterone a mass spectrum was obtained.