Fetal "gallstones" are still an unsolved mystery. Case series.

Background: Echogenic content in the fetal gallbladder is rather an incidental finding during third-trimester ultrasonography. The etiology, clinical course, and prognosis of this condition are still unclear. We highlight the demographic, clinical and ultrasound characteristics of our patients with echogenic content in the fetal gallbladder.

Methods: This is a retrospective single-center study conducted at the University of Medicine and Pharmacy Cluj-Napoca, Romania, between March 2022 and April 2023. All pregnant patients who were admitted to the hospital and had echogenic content in the fetal gallbladder detected by ultrasound were identified. The clinical and ultrasonography parameters were obtained from the databases of the ultrasound units and the medical records of the patients.

Results: Four patients were found to have echogenic content in the fetal gallbladder. The mean maternal age at diagnosis was 27.5 years (range 25-31). All patients had singleton pregnancies. The mean gestational age at diagnosis was 36.5 weeks (range 35-40). In all cases, the predominant aspect of echogenic content on ultrasound was multiple hyperechogenic foci; additionally, in one case, sludge was also observed. The mean maximal length of the hyperechogenic foci was 3.375 mm (range 1.6-5.4). All fetuses were delivered at full term, either vaginally or by cesarean section. The mean weight at birth was 3082.5 g (range 2800-3450). In all four cases, the EC disappeared spontaneously at birth. Neither of the four newborns displayed digestive symptoms or complications during the follow-up.

Conclusion: The EC is still a medical mystery since little is known about its etiology and long-term outcome. Many cases are likely to be undetected until after birth; therefore, fetal gallbladder examination should be included in the US routine. The condition appears to be benign, and usually, it improves naturally after birth. Consecutively, asymptomatic newborns with EC can be managed through a wait-and-see approach.