EP29.08: Outcome of Non‐visualisation of Fetal Gallbladder

Non-visualization of the fetal gallbladder (NVFGB) on prenatal ultrasound is uncommon and in most cases it is detected eventually. It can be associated with cystic fibrosis (CF) and biliary atresia. During the study period (2015-2022) we collected cases of NVFGB in the second trimester. Cases with no additional malformations were designated as isolated. Further evaluation included follow-up scans and search for fetal anomalies. Patients with additional malformations were offered genetic consultation and amniocentesis. CF testing was also included. We collected 13 cases of NVFGB,7 were isolated and 6 had additional malformations. In 1 of these 5, the pregnancy was terminated for chromosomes 4 and 22 duplication-deletion. The first patient associated an hyperechogenic bowel, with a normal GB at birth but diagnosed with cystic fibrosis. The second one associated an early-onset IURG and had a normal GB at birth, but was diagnosed with CHARGE syndrome. Other patient was diagnosis with a mitral-aortic atresia but she decided to continue the pregnancy; the abdominal ultrasound revealed a normal GB but the baby died after three months due to her heart disease. The last patient with additional malformations had a single umbilical artery and polyhydramnios; we performed an MRI which ruled out and esophageal atresia. At birth, the newborn was diagnosed with GB agenesis and esophageal atresia; the surgery was successfully performed and the child is alive and well after 2 years. In 3 of the isolated cases, GB was detected by ultrasound antenatally. There are 3 cases of GB hypoplasia/agenesis. There were no diagnoses of biliary atresia among cases of isolated NVFGB and the children are asymptomatic after 7 years to 3 months of follow-up. There are two ongoing pregnancies, one isolated and the other one with associated malformations. When NVFGB is associated with other malformation, the risk of a severe postnatal condition should be considered. A detailed ultrasound scan, a karyotyping test and parents tested for CF gene mutation must be offered. When it is isolated and CF is ruled out, the outcome is good.