The fetus of a 30-year-old pregnant Japanese woman was diagnosed with absence of inferior vena cava (IVC) and azygos continuation of interrupted IVC without cardiac anomalies at 34 weeks of gestation, and a healthy male neonate weighing 2,910 g was delivered at 37 weeks of gestation. On day 42 after birth, direct bilirubin predominant hyperbilirubinemia and high serum gamma-GTP levels were detected. Computed tomography revealed the presence of a lobulated and accessory spleen, and laparotomy demonstrated type III biliary atresia (BA), confirming the final diagnosis of BA splenic malformation (BASM) syndrome. In retrospect, non-visualization of the gallbladder was missed in utero. The combination of the absence of IVC and BA without cardiac anomalies is far less likely to occur in left isomerism. Although BA remains difficult to detect in utero, special attention should be paid to cases of BA associated with findings of left isomerism, including the absence of IVC, to enable early diagnosis and treatment of BASM.
Keywords: biliary atresia; inferior vena cava; isomerism; prenatal diagnosis; ultrasonography.