Large fetal gallbladder may be caused by examination error, fetal malformation, physiological enlargement and other factors. 1. Examination error: the accuracy of ultrasound examination is affected by the experience and technique of the doctor. A single examination during pregnancy indicating a large fetal gallbladder may be due to examination error, and further screening is recommended to determine if the gallbladder is large. 2. Fetal anomalies: The fetus not only has a large gallbladder, but also has fetal anomalies such as congenital absence of bile ducts or biliary atresia, in which case the baby’s gallbladder will be found to be persistently enlarged and progressively aggravated during repeated examinations. 3. Physiological enlargement: The congenital larger gallbladder of the fetus, and there is no other malformation, may be the problem of the development of the gallbladder itself, generally do not need to worry too much. Abnormalities in the pregnancy examination require prompt medical attention for further examination and, if necessary, treatment under the guidance of a doctor.