Abstract / Summary
Background: Peak total bile acids guide management of intrahepatic cholestasis of pregnancy (ICP), potentially influencing observed outcomes. We examined their association with a composite adverse perinatal outcome (CAPO) excluding preterm delivery. Methods: This retrospective cohort included 280 singleton pregnancies with ICP delivered at a tertiary hospital between January 2023 and May 2026. Peak bile acids were categorized as <40, 40–99, or ≥100 µmol/L. CAPO comprised meconium-stained amniotic fluid, nonreassuring fetal status, neonatal intensive care admission, respiratory distress syndrome, transient tachypnea, neonatal death, or intrauterine fetal death. Logistic regression and receiver operating characteristic analysis were performed; the exploratory threshold maximized the Youden index. Results: The categories included 185, 70, and 25 pregnancies, with CAPO in 31 (16.8%), 19 (27.1%), and 19 (76.0%), respectively (p < 0.001). In the ≥100 µmol/L group, the exact 95% confidence interval for CAPO was 54.9–90.6%. The apparent area under the curve was 0.700 (95% confidence interval 0.625–0.772). The 61.3 µmol/L threshold yielded 50.7% sensitivity and 83.9% specificity. Peak bile acids per 10 µmol/L (adjusted odds ratio 1.20, 95% confidence interval 1.11–1.31) and hypertensive disorders (3.27, 1.30–8.23) were independently associated with CAPO. Conclusions: Peak bile acids showed moderate discrimination within this managed cohort. The ≥100 µmol/L subgroup had higher morbidity but imprecise estimates. The same-cohort-derived 61.3 µmol/L threshold is exploratory and requires independent validation; it should not determine delivery timing.