title: Perinatal bile acid metabolism: analysis of urinary bile acids in pregnant women and newborns.
abstract: The metabolism of bile acids in 30 pregnant women was evaluated by analyzing the urinary composition of bile acids during late gestation (weeks 30-41) and again in these women and their newborn infants during the first week after delivery. The levels of individual bile acids were determined by gas chromatography-mass spectrometry after solvolysis and hydrolysis of bile acid conjugates. The mean total bile acid/creatinine ratio in pregnant women decreased from 1.22 micromol/mmol creatinine at 30-32 weeks of gestation to 0.15 micromol/mmol creatinine at 6-7 days after delivery. The mean percentage of 1beta-hydroxylated bile acids peaked at 27% at 3-4 days after delivery. In newborn infants, the mean total bile acid/creatinine ratio rapidly increased from 3.39 micromol/mmol creatinine at birth to 54.33 micromol/mmol creatinine at 7 days. During this period, large amounts (40-50%) of unsaturated ketonic bile acids, especially 7alpha,12alpha-dihydroxy-3-oxo-5beta-chol-1-en-24-oic acid and 7alpha,12alpha-dihydroxy-3-oxo-4-cholen-24-oic acid, were observed in the infants' urine. These data suggest that, during the perinatal period, the formation of polyhydroxylated and unsaturated ketonic bile acids probably represents a mechanism for the excretion of bile salts, and that the metabolism of bile acids in both the mother and the infant changes significantly after birth.
authors.affiliation: Department of Pediatrics and Child Health, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Murai
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.forename: D
authors.initials: D
authors.lastname: Hori
authors.forename: Y
authors.initials: Y
authors.lastname: Nomura
authors.forename: T
authors.initials: T
authors.lastname: Yoshimura
authors.forename: T
authors.initials: T
authors.lastname: Kurosawa
authors.forename: M
authors.initials: M
authors.lastname: Tohma
mesh_terms: D000328:Adult; D001647:Bile Acids and Salts / Q000737:chemistry / Q000378:metabolism / Q000652:urine*; D002793:Cholic Acids / Q000652:urine; D003404:Creatinine / Q000652:urine; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn / Q000652:urine*; D007536:Isomerism; D011247:Pregnancy / Q000652:urine*
chemical_list: D001647:Bile Acids and Salts; D002793:Cholic Acids; D003404:Creatinine