Diagnostic and prognostic value of transaminase complex-platelet ratio in intrahepatic cholestasis of pregnancy: A novel composite index based on routine blood tests.

Objective: The study aims to evaluate the transaminase complex-platelet ratio (TACPR), a novel composite biomarker derived from routine laboratory parameters, in its ability to serve as a predictor of intrahepatic cholestasis of pregnancy (ICP) and related adverse perinatal outcomes.

Materials and methods: This retrospective study included 98 pregnant women diagnosed with ICP and 100 matched healthy controls at a tertiary referral center between January 2024 and March 2025. TACPR was calculated as (alanine aminotransferase x aspartate aminotransferase)/platelet count. Groups were compared in terms of clinical characteristics, TACPR values (first trimester and diagnosis), and perinatal outcomes. Receiver operating characteristic analysis and multivariate logistic regression were used to assess predictive performance and independent risk factors for ICP and composite adverse perinatal outcomes (CAPO).

Results: TACPR values were significantly higher in the ICP group at both time points (p<0.001). In the first trimester, a TACPR >1.35 predicted ICP [area under curve (AUC)=0.806], while a TACPR >1.81 predicted CAPO (AUC=0.759). At diagnosis, a TACPR >27.7 predicted severe ICP and a TACPR >7.15 predicted CAPO. TACPR >1 in the first trimester was independently associated with ICP [odds ratio (OR)=5.49, p<0.001], and TACPR >50 at diagnosis was independently associated with CAPO (OR=4.38, p=0.009). A weak yet statistically significant correlation was identified between first trimester TACPR and peak serum bile acid levels (r=0.325, p=0.001).

Conclusion: TACPR is a novel, cost-effective biomarker for early identification and risk stratification of ICP and associated perinatal complications. Its integration into routine prenatal screening may enhance timely diagnosis and intervention, particularly in resource-limited settings.