P24.15: Non‐visible gallbladder during the second half of pregnancy: case report

Non-visualization of the fetal gallbladder (NVFGB) on the ultrasound (US) scan, during the second half of pregnancy, is an uncommon event. Most of the times, this structure can be finally identified, pre- or postnatally, in a second assessment. Nevertheless, NVFGB has also been associated to agenesis of the gallbladder, biliary atresia, cystic fibrosis (CF) and aneuploidies. We're presenting a series of 4 cases of NVFGB. In all cases, this finding was described during the 20-22 weeks anomaly scan. In one patient this was an isolated finding, fetal cfDNA analysis in maternal blood and CF carrier testing in the parents retrieved normal results and amniocentesis was therefore not done; a postnatal US scan showed a malformed gallbladder (small and lobulated) and also biliary atresia was ruled out. The other 3 cases had other US findings associated and an amniocentesis was performed: The first fetus had a persistent right umbilical vein, karyotype was found normal, CF was discarded and postnatal US scan at 5 months of postnatal life showed a normal gallbladder. The second one had a right cleft lip-palate and the karyotype showed a deletion compatible with Wolf-Hirschhorn syndrome (which associates facial anomalies, mental retardation and early death). The third case showed a mild dilation of the bowel and the intrahepatic bile duct on the US scan; karyotype and testing for CF were normal; prenatal MRI detected a small gallbladder; postnatal US scan was normal and the overall outcome was favourable. NVFGB usually implies a good prognosis. Nevertheless, it seems recommendable to perform a study of fetal karyotype and testing for CF and biliary atresia, especially if there are other US anomalies associated.