Urinary excretion of 5beta-pregnane-3alpha,20alpha,21-triol in human gestation

The steroids in urine from normal pregnant women have been studied. After extraction of conjugate steroids, solvolysis and enzymatic hydrolysis, the liberated steroids were separated by chromatography on Sephadex LH-20, and were analysed by gas-liquid chromatography and gas chromatography mass spectrometry. The following steroids were isolated and completely identified in the LH-20 fraction 7: 5beta-pregnane-3alpha,20alpha-diol, 5beta-pregnane-3alpha,17,20alpha-triol, 5beta-pregnane-3alpha,20alpha,21-triol and 5alpha-pregnane-3beta,16alpha,20alpha-triol. In addition, two metabolites tentatively identified as 5xi-pregnane-2xi,3xi,20xi-triol and 2xi,3xi,16xi-trihydroxy-5xi-pregnan-20-one, have not been reported as occcurring in urine from pregnant women. The 5beta-pregnane-3alpha,20alpha,21-triol was detected only in the third trimester of pregnancy and the urinary excretion values are between 320 and 650 microgram per 24 h. With the present data, it is not possible to establish the precursor(s) of this steroid. However, these results tentatively suggest that 5beta-pregnane-3alpha,20alpha,21-triol arises from foeto-placental unit.