[Detection of 3 beta-hydroxy-5-cholenoic acid in human amniotic fluid]. 
Studies of the bile acids of human meconium suggest that a fetal pathway of bile acid synthesis exists which leads to formation of 3beta-hydroxy-5-cholenoic acid, a bile acid not found in serum of healthy pregnant women.  To obtain additional support for this hypothesis, cholic, chenodeoxycholic, and 3beta-hydroxy-5-cholenoic acid were measured in amniotic fluid specimens from 18 pregnant women without liver disease.  The finding of a considerable percentage of 3beta-hydroxy-5-cholenoic acid (mean: 34 molar %; range 3-71 molar % of total bile acids) in amniotic fluid strengthens the hypothesis that a fetal pathway of bile acid synthesis exists which begins with oxidation of the cholesterol side chain.