Sludge in fetal gallbladder: natural history and neonatal outcome.

Normal and pathological conditions of the fetal gallbladder have been a subject of recent investigation by ultrasonographers. Fetal gallstones are the most common abnormal finding and appear as echogenic foci within the gallbladder. We report a series of five fetuses in whom the gallbladders were filled with sludge which appeared as a pear shape echogenic structure. In the majority of cases, gallbladder sludge mimicked intrahepatic calcification or echogenic bowel. Serial ultrasound examinations of these fetuses revealed good interval growth. The gallbladders remained echogenic and were normal in size in three cases and were moderately enlarged in two. All neonates were born in normal condition with no identifiable malformations. Follow-up was obtained in four infants using abdominal ultrasound. A normal appearing sludge free gallbladder was seen in three neonates at 6 weeks of life and in four infants at 12 weeks. Accurate diagnosis of gallbladder sludge will spare the patient unnecessary work-up and anxiety. The natural history of gallbladder sludge in the fetus is benign in nature and is similar to that of fetal gallstones.