Determining Urinary Bile Acid Profiles to Predict Maternal and Neonatal Outcomes in Patients with Intrahepatic Cholestasis of Pregnancy

<b>Objective</b>: Intrahepatic cholestasis of pregnancy (ICP) is associated with an elevated risk of adverse perinatal outcomes, including perinatal morbidity and mortality. The objectives of this study were to evaluate the bile acid (BA) metabolism profiles in the urine of patients with ICP and to investigate the association between specific BAs and maternal and neonatal outcomes in patients with ICP. <b>Methods:</b> A total of 127 Chinese women with ICP and 55 healthy pregnant women were enrolled in our retrospective study. Spot urine samples and clinical data were collected from pregnant women from January 2019 to December 2022 at the First Affiliated Hospital of Chongqing Medical University, Chongqing. Based on total bile acid (TBA) levels, the ICP group was subdivided into mild (10-40 μmol/L) and severe (≥40 μmol/L) ICP groups. Patients in the ICP group were further divided into two categories according to neonatal outcomes: an ICP with adverse pregnancy outcomes group and an ICP with non-adverse pregnancy outcomes group. Metabolites from maternal urine were collected and analyzed using ultra-high-performance liquid chromatography-triple quadrupole time-of-flight mass spectroscopy (UPLC-triple TOF-MS). <b>Results:</b> Significant differences were observed between the mild and severe ICP groups in the onset time of symptoms, gestational weeks at time of ICP diagnosis, the duration of using ursodeoxycholic acid (UDCA) drugs during pregnancy, gestational age at delivery, premature delivery, and cesarean delivery. The expression levels of the composition of different urinary bile acids including THCA, TCA, T-ω-MCA, TCA-3-S, TCDCA-3-S, TDCA-3-S, GCDCA-3-S, DCA-3-G and GDCA-3-G were remarkably higher in the ICP with adverse pregnancy outcomes group than those in the ICP with non-adverse pregnancy outcomes group and the control group. The single-parameter model used to predict adverse pregnancy outcomes in ICP had similar areas under the curve (AUCs) of the receiver operating characteristic (ROC), ranging from 0.755 to 0.869. However, an AUC of 0.886 and 95% CI were obtained by the index of combined urinary bile acids in multiple prediction models (95% CI 0.790 to 0.983, <i>p</i> < 0.05). TCA-3-S in the urinary bile acids had a strong positive correlation with the aspartate aminotransferase (AST) level (<i>r</i> = 0.617, <i>p</i> < 0.05). Furthermore, TCDCA-3-S and GCDCA-3-S in the urinary bile acids had a strong positive correlation with the alanine aminotransferase (ALT) level (<i>r</i> = 0.607, <i>p</i> < 0.05; <i>r</i> = 0.611, <i>p</i> < 0.05) and AST level (<i>r</i> = 0.629, <i>p</i> < 0.05; <i>r</i> = 0.619, <i>p</i> < 0.05). <b>Conclusions:</b> Maternal urinary bile acid profiles were prominent for the prognosis of maternal and neonatal outcomes of ICP. Elevated levels of TCA-3-S, TCDCA-3-S, and GCDCA-3-S in urine might be important predictors for indicating adverse pregnancy outcomes in ICP.