Diagnosis of fetal congenitally unguarded tricuspid valve orifice by echocardiography.

Objective: To review the imaging characteristics and evaluate the diagnostic value of echocardiography for fetal congenitally unguarded tricuspid valve orifice (CUTVO).

Methods: Doppler echocardiography was performed and the images were compared with operative and necropsy findings in ten fetuses with CUTVO. The aim of the study was to summarize the characteristics of fetal echocardiography and analyze the causes of missed diagnoses and misdiagnoses.

Results: There were six cases with complete absence (60%) and four cases with partial absence of the tricuspid leaflet (40%). Among all cases, six cases were consistent with the ultrasonic diagnosis. CUTVO ultrasonographic characteristics consist of the atrioventricular connection with normal arteries and the tricuspid valve device partially or completely absent. The annulus of the tricuspid valve can be described as "empty" in the apical four-chamber view, Doppler evaluation shows to-and-fro flow across the tricuspid orifice with low velocity and two-way spectrum.

Conclusion: Fetal echocardiography can accurately diagnose CUTVO, but missed diagnosis and misdiagnosis should be reduced.