OBJECTIVES: The aim of this study is to examine the value of the first-trimester aspartate aminotransferase to platelet ratio index (APRI) score in predicting intrahepatic cholestasis of pregnancy (ICP) occurring later in pregnancy. Another aim of the study is to determine the relationship between APRI scores and total bile acid (TBA) levels in pregnant women with ICP. STUDY DESIGN: This retrospective case-control study was conducted by examining the hospital records of women diagnosed with ICP (n=66) and healthy controls (n=70) among women followed during pregnancy. Hemoglobin (Hb), platelet count (PLT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) values of all patients were obtained from routine blood test data taken in the first and third trimesters. The first and third-trimester APRI scores of the patients were calculated. Demographic data, laboratory findings, and APRI scores of women with and without ICP during pregnancy were compared. Using Roc analysis, the values of AST, ALT, PLT values, and APRI scores were examined in predicting ICP among the first trimester findings of the patients. In addition, TBA levels of patients with ICP at the time of diagnosis were obtained from hospital records. The relationship between the first and third-trimester APRI scores and TBA levels in patients with ICP was evaluated using correlation analysis. RESULTS: In the first and third-trimester laboratory values, AST and ALT levels and APRI scores were found to be higher and PLT values were lower in patients with ICP compared to healthy controls. Among the first trimester measurements of these data, the APRI score had the highest predictive value in predicting ICP (AUC values are 0.648 for AST, 0.655 for ALT, 0.633 for PLT, and 0.705 for APRI). In an examination of patients with ICP, the APRI score calculated in the first and third trimesters showed a positive correlation with the TBA level at diagnosis (r=0.435 p<0.001 for the first trimester and r=0.433 p<0.001 for the third trimester in the Spearman analysis). CONCLUSIONS: In the future, the APRI score calculated in the first trimester of pregnancy may be used as a tool to predict ICP that may occur in the following weeks. There may be a positive correlation between APRI score and serum TBA level in patients with ICP.