First Trimester Tricuspid Regurgitation: Clinical Significance

Abstract

Tricuspid regurgitation is a cardiac valvular anomaly that consists of the return of blood to the right atrium during systole due to incomplete valve closure. This structure can be visualized on ultrasound between 11 and 14 weeks of gestation in most cases. Despite being a common finding, even in healthy fetuses, the presence of tricuspid regurgitation may be associated with chromosomal and structural abnormalities. The evaluation of tricuspid flow and the presence of regurgitation on first-trimester ultrasound has shown promising results regarding its role in the early detection of aneuploidies, congenital heart defects, and other adverse perinatal outcomes. This review article aims to demonstrate the importance of tricuspid regurgitation as a secondary marker, and consequently, significant benefits of its early detection when added to the combined first-trimester screening. Its value will be discussed, namely its sensitivity and specificity, alone and together with other current markers in the fetal assessment performed in the first-trimester ultrasound.

Keywords: Doppler; chromosomal abnormality; congenital heart defect; fetal echocardiography; tricuspid regurgitation; tricuspid valve.

Fig. (1)

Flowchart of the search results.

Fig. (2)

Embryology of atrioventricular valves. Valvulogenesis begins with the formation of endocardial cushions in the regions of AVC (atrioventricular canals). Two cushions form in the AVC, an anterior and a posterior, which fuse. (A, lateral view) A mesenchymal cushion appears on the lateral myocardial wall of the AVC, resulting in a mural leaflet. A septal leaflet emerges from the fusion of the anterior and posterior cushions. The previous structures will form the atrioventricular valves (mitral and tricuspid). (B, front view) RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle.

Fig. (3)

Tricuspid valve anatomy. The tricuspid valve location is between the atrium and right ventricle. It consists of three leaflets, the anterior, which extends from the infundibular area to the inferolateral wall of the right ventricle; the septal, connected to the membranous and muscular portion of the ventricular septum; and the posterior, located along the posteroinferior border of the tricuspid annulus. The valve is associated with a valvular apparatus, made up of the fibrous annulus, one of the components of the heart’s fibrous skeleton, the tendinous chords, and the papillary muscles, which are usually three: the anterior, posterior, and septal muscles.

Fig. (4)

Color and pulsed Doppler examination across the tricuspid valve. Doppler velocity waveforms across the tricuspid valve at 13 weeks of gestation in a normal fetus (A) and in a fetus with trisomy 21 with severe tricuspid regurgitation (B).