Nonvisualization of the Fetal Gallbladder: Can Levels of Gamma-Glutamyl Transpeptidase in Amniotic Fluid Predict Fetal Prognosis?

Objective: In cases of nonvisualization of the fetal gallbladder (NVFGB), we investigated whether amniotic fluid levels of gamma-Glutamyl transpeptidase (GGTP) can distinguish normal development or benign gallbladder agenesis from severe anomaly such as biliary atresia.

Methods: This is a retrospective cohort study of pregnancies in which the gallbladder was not visualized in the second-trimester fetal anatomy scan. Levels of GGTP in amniotic fluid were analyzed prior to 22 weeks of gestation by amniocentesis. Data were collected regarding other fetal malformations, fetal karyotype, and screening results for cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations.

Results: Of 32 cases of NVFGB, 27 (84%) had normal GGTP levels and a normal CFTR gene screening, and 1 of them had an abnormal karyotype. Three of the 5 cases with low GGTP were diagnosed with extrahepatic biliary atresia, proven by histopathological examination following termination of pregnancy. The fourth case had hepatic vasculature abnormality and the fifth isolated gallbladder agenesis. In 22 of 32 cases (68.7%), the gallbladder was detected either later in pregnancy or after delivery.

Conclusion: The findings support low levels of GGTP in amniotic fluid, combined with NVFGB, as a sign of severe disease, mainly biliary atresia. Normal GGTP levels, concomitant with isolated NVFGB, carry a good prognosis.