Gallstones in adults and children grow at about 1 to 2 mm per year, occurring many years before clinical symptoms appear. Gallstones do not continually form in the gallbladder but probably nucleate as crops of stones that then grow at the same rate 5 . Most gallstones are clinically silent. Gallbladder motility decreases once stones develop. Some, but not all, patients with cholelithiasis have impaired gallbladder emptying 5 .
Fetal gallstones have a tendency to form in the third trimester of pregnancy.
We observed gallstones in a 26 week fetus, which represents the earliest reported case in the literature. The fact that we were able to detect gallstones in the bile ducts may favor the first hypothesis in which fetal gallstones are passed. Regardless of the mechanism, total resolution of fetal gallstones is not universal. Some gallstones diagnosed in utero may persist for several months and years 1 . Fetal gallstones, including those in the bile ducts, are rare but benign findings which should be differentiated from intrahepatic calcifications which can be associated with an adverse perinatal outcome.