Profile of bile acids in fetal gallbladder and meconium using liquid chromatography-tandem mass spectrometry

The primary bile acids found in meconium vary with the gestational age of the fetus and the intestinal location of the meconium. We determined the composition of bile acids in samples that were collected from the gallbladder and intestine.

The bile-acid profiles of intestinal contents and the gallbladder were obtained from nine fetuses who died from abortion or respiratory failure within 72 h after birth. Intestinal content samples were collected from seven intestinal locations. The bile-acid profiles of meconium were also obtained from seven full-term live births for comparison. The profiles were analyzed using liquid chromatography-tandem mass spectrometry.

The bile acids in meconium collected from stillborn and live births were mainly chenodeoxycholic acid and cholic acid, conjugated with taurine, glycine, and sulfate. The same bile acids were found in the gallbladder, except that sulfate was not found.

Sulfate-conjugated bile acid is found in urine, but rarely in stool. In this study, the gallbladder bile acid contained no sulfate conjugates, but these were present in intestinal contents and meconium. These results indicate that sulfate-conjugated bile acids are not excreted into the intestine through the biliary tract but originate from swallowed amniotic fluid that contains fetal urine.