Case Report: Fetal Congenital Right Atrial Appendage Aneurysm With 2-Year Postnatal Follow-Up.

Congenital right atrial appendage aneurysm (RAAA) represents a rare cardiac anomaly whose exact etiology, prognostic implications, and optimal management remain undetermined. RAAA characteristic echocardiographic features include a cystic structure demonstrating continuity with the right atrial chamber, with confirmed hemodynamic communication between the two structures. While fetal RAAA is typically detected during the third trimester of pregnancy, our case represents an unusually early diagnosis during the first trimester, with comprehensive longitudinal follow-up extending to 2 years postnatally. Notably, this case revealed a potential association with chromosome 1 abnormalities, suggesting a possible genetic component in the pathogenesis of this condition.