Ultrasonographic evaluation of the gallbladder motor function in the diagnosis and prognosis of intrahepatic cholestasis of pregnancy.

ABSTRACT

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is characterized by skin pruritus, elevated liver enzymes, and increased serum total bile acids. Several previous studies have revealed that the fasting and ejection volumes of the gallbladder in cholestasis of pregnancy are greater than those in normal pregnancy. The goal of this study was to explore the gallbladder volume and evaluate the diagnostic and prognostic value of ultrasound in ICP. METHODS: We prospectively recruited a cohort of 60 ICP patients at the First Affiliated Hospital of Xi'an Jiaotong University, Shaanxi, China from January 2020 to December 2021 and compared their data with those from healthy pregnant women (n = 60). The gallbladder volume was evaluated by real-time ultrasound examination after overnight fasting and at 30, 60, 120, and 180 min after a liquid test meal of 200 mL, and the ejection fraction was calculated. Continuous data between two groups were compared by Student's t test. Differences were considered significant for p < 0.05. The diagnostic and prognostic value of the volume and ejection function of the gallbladder was analyzed by the receiver operating characteristic (ROC) curve. RESULTS: The ICP group had significantly higher gallbladder basal volume (43.49 ± 1.34 cm3 vs. 26.66 ± 0.83 cm3, p < 0.01) and higher ejection fraction compared with the healthy group. The ejection fraction higher than 54.55% at 120 min might predict ICP diagnosis with 96.67% sensitivity and 88.33% specificity, and an AUC of 0.9739 (95% CI 0.9521-0.9956), while the gallbladder volume higher than 12.52 cm3 at 60 min might predict ICP severity with 59.18% sensitivity and 72.73% specificity, and an AUC of 0.7319 (95% CI 0.5787-0.8852). CONCLUSION: Our results indicate abnormal volume and ejection function of the gallbladder in patients with ICP. The ejection fraction at 120 min can assist in the diagnosis if ICP exists, and the gallbladder volume at 60 min may assess the degree of severity of ICP.