Prenatal sonographic spectrum and first-trimester diagnostic features of Ebstein anomaly: A descriptive case series

This descriptive case series aimed to delineate the prenatal sonographic spectrum of Ebstein anomaly (EA) across all trimesters, analyze common diagnostic pitfalls, and propose systematic imaging clues for first-trimester detection.

In this retrospective study, 40 fetuses with EA were included. A standardized echocardiographic protocol integrating transvaginal imaging for the first trimester (n = 7) and multiplanar analysis for the second and third trimesters (n = 33) was applied. Key morphological and functional parameters were documented.

The sonographic spectrum ranged from mild forms with isolated leaflet displacement to severe forms with marked cardiomegaly. In the first trimester, severe cases presented with a recognizable tetrad: (1) leftward cardiac axis deviation (>65°), (2) right atrial enlargement, (3) shortened/displaced septal leaflet with elongated anterior leaflet, and (4) severe low-origin tricuspid regurgitation. Common diagnostic challenges included isolated posterior leaflet displacement, hemodynamic confounders, and confusion with other right heart anomalies.

This study describes the detailed prenatal sonographic spectrum of EA and proposes a structured imaging workflow. The identified first-trimester features may serve as preliminary clues for early detection of severe cases, although their diagnostic accuracy requires validation in prospective studies. These findings underscore the importance of a systematic, multiplanar examination to minimize diagnostic errors.