[Developmental profile of urine bile acids in preterm infants].

To investigate a developmental profile of urinary 1 beta-hydroxylated cholic acid of preterm infants, a urinary 1 beta-hydroxylated cholic acid/total bile acid ration (%) was measured in 118 preterm infants using Gas Chromatography- Mass Spectrometry (GC-MS). Following results were obtained: (1) The mean value of urinary 1 beta-hydroxylated cholic acid/total bile acid ratio (%) increased rapidly from birth to 0 weeks of corrected postnatal age (Expected date of confinement was denoted as day 0), and decreased thereafter. Thus the mean ratio (%) at week 0 was approximately 50%, and it became less than 10% at week 40. (2) The earlier the gestational weeks of preterm infants at birth were, the smaller the ratio (%) was. (3) The developmental profile of the urinary 1 beta-hydroxylated cholic acid/total bile acid ratio (%) from birth to 110 weeks of corrected postnatal age had almost the same pattern regardless of gestational weeks at birth, weight at birth and whether it was small-for-gestational-age (SGA) or appropriate-for-gestational-age (AGA) in preterm infants. (4) The developmental profile of the urinary 1 beta-hydroxylated cholic acid/total bile acid ratio (%) from birth to 110 weeks of corrected postnatal age had a similar pattern between males and females, although the mean ratios at -13, -10, -5, 0, 20, 60 and 80 weeks of corrected postnatal age of the female group tended to be consistently higher than those of the male group in preterm infants. Based on these results, a possible application of the present analysis in diagnosing hepato-biliary disorders is being investigated.