Prediction Of Fetal Biliary Atresia By Second And Third Trimester Ultrasound Characteristics

Objective:A limited number of studies have addressed the prenatal ultrasound findings of biliary atresia,and these findings have mainly been based on retrospective studies and case reports.The potential role of prenatal ultrasound in the prediction of biliary atresia needs to be systematically studied,and a prospective study is needed to identify the specific sonographic features that are related to biliary atresia.The purpose of this study was to explore the diagnostic performance of prenatal ultrasound in the prediction of biliary atresia.Methods:During the study period from January 2017 to February 2020,we prospectively collected cases of suspected biliary abnormalities in the 2^nd trimester of pregnancy（Cases include non-visualization of fetal gallbladder,bile duct cysts,and abnormally large or small gallbladder）,and performed a series（at least 3）of prenatal ultrasound examinations in the 2^nd and 3^rdtrimester.The presence of the gallbladder was examined each time,and its size and shape were assessed if the gallbladder was visible.The existence of biliary cysts,dilated hepatic arteries,and other abnormalities were carefully evaluated.Neonatal ultrasound examination was conducted within 1month after birth,and clinical data and surgical results were followed-up for 6 months after birth.Results:Among the 41895 patients,298 were suspected to have biliary abnormalities,while 82 patients were excluded due to loss of follow-up or induced labor caused by other abnormalities.A total of 216 patients were included in this study,and 15 were diagnosed with BA.We summarized the ultrasound findings of the gallbladders,and defined a high-risk gallbladder for the prenatal diagnosis of BA.This was demonstrated to have the best diagnostic performance as a single parameter,with an area under the curve of 0.914（95%CI:0.869-0.948）.In addition,higher incidences of biliary cysts,right hepatic artery dilation,echogenic bowel,and seroperitoneum were observed in BA fetuses.Logistic regression analysis showed that the combination of 5parameters had better diagnostic performance,with an area under the curve of 0.995（95%CI:0.973-0.999）.Conclusion:The fetal gallbladder was found to be a critical feature for identification of biliary atresia.Concomitant abnormalities including biliary cysts,hepatic artery dilatation,and echogenic bowel could be helpful to improve the accuracy of the diagnosis.