Abstract: Objective To investigate the diagnostic efficacy of ultrasonic cord blood flow parameters alongside serum activin A (ActA), malondialdehyde (MDA) and superoxide dismutase (SOD) levels for detecting fetal distress (FD) in patients with intrahepatic cholestasis of pregnancy (ICP). Methods Between October 2020 and October 2022, our hospitall enrolled 106 pregnant women diagnosed with ICP. These participants were categorized based on childbirth outcomes into a FD group (45 cases) and a non-FD group (61 cases). Prior to delivery, all subjects underwent ultrasonography and serological assessments. This study compared the levels of end-systolic maximum blood velocity (S)/end-diastolic maximum blood velocity (D), resistance index (RI), pulsation index (PI), ActA, MDA and SOD between the two groups. The diagnostic utility of S/D, RI, ActA, MDA and SOD for FD in ICP patients were evaluated using ROC curve analysis. Additionally, the combined diagnostic accuracy of S/D, RI , ActA, MDA and SOD was assessed for consistency. Results No significant difference was observed in the PI levels between the FD group [(0.56±0.14)] and the non-FD group [(0.60±0.13)] (P>0.05). However, the FD group showed significantly higher levels of S/D, RI, ActA and MDA[(3.08±0.53), (0.66±0.14), (0.46±0.14) pg/L, (4.27±0.62) μmol/L respectively] compared to the non-FD group [(2.57±0.61), (0.45±0.11), (0.32±0.10) pg/L, (3.38±0.57) μmol/L respectively]. Conversely, SOD levels were significantly lower in the FD group [(33.96±3.87) kU/L] than in the non-FD group [(44.75±4.61) kU/L, P<0.05]. ROC curve analysis confirmed the diagnostic capability of S/D, RI, ActA, MDA and SOD in detecting FD, with areas under the curve of 0.730, 0.800, 0.784, 0.837 and 0.884 respectively, all significant(P<0.05). The optimal cut-off values for these markers were 2.635, 0.505, 0.395 pg/L, 3.850 μmol/L, and 39.480 kU/L respectively, with sensitivities of 0.884, 0.800, 0.711, 0.733, and 0.778. Consistency analysis showed that combining S/D, RI, ActA, MDA and SOD improved diagnostic sensitivity, specificity, accuracy, and Kappa to 0.911, 0.967, 0.943 and 0.883, respectively. Conclusion The diagnostic parameters of umbilical cord blood flow, specifically the S/D, RI, along with serum markers ActA, MDA, and SOD, are effective in identifying FD in patients with ICP. The combined use of these markers significantly enhances diagnostic accuracy.

Key words: Intrahepatic cholestasis of pregnancy, Fetal distress, Umbilical cord blood flow, Activin A, Malondialdehyde