ABSTRACT

We qualitatively and quantitatively evaluated unusual bile acids such as unsaturated ketonic, polyhydroxylated, and 3β-hydroxylated bile acids in urine from preterm and full-term infants by gas chromatography-mass spectrometry with selected ion monitoring. We found that the urinary concentration and proportion of 3β-monohydroxy-Δ⁵-bile acids did not differ between early preterm, late preterm and full-term infants. However, the percentage of ketonic bile acids in urine was higher in late preterm and ful-term infants than in early preterm infants. We concluded that activation of the classical pathway for bile acid biosynthesis may increase near the time of delivery, with the pathway predominating after birth. Nonetheless, the acidic pathway for bile acid biosynthesis remains after birth as well as in the fetus.