Objective: To assess the feasibility of ultrasound identification of aortic valve anatomy in the fetus, with particular emphasis on the detection of bicuspid aortic valve.
Methods: This study was a prospective analysis of 21 fetuses with prenatally diagnosed congenital left heart obstructive lesions and 45 normal fetuses undergoing routine ultrasound evaluated at a tertiary referral center. These fetuses underwent detailed echocardiography, including the study of the aortic valve on a targeted short-axis view of the right ventricle. Necropsies or postnatal echocardiograms were available for confirmation of the diagnosis in all cases.
Results: Aortic cusps and commissures were satisfactorily visualized in 38/45 (84%) normal fetuses and in 18/21 (86%) fetuses with congenital heart disease. The aortic valve was correctly defined as bicuspid in one normal fetus and in six fetuses with congenital heart disease. In two fetuses with a positive family history, the bicuspid aortic valve was isolated. There was one incorrect diagnosis (a unicuspid unicommissural valve diagnosed prenatally as a bicuspid aortic valve in a fetus with severe aortic stenosis) and one false-positive diagnosis in a fetus diagnosed with a coarctation and a bicuspid aortic valve late in the third trimester of pregnancy and in which both anomalies were not confirmed at neonatal echocardiography.
Conclusions: This study demonstrated that aortic valve anatomy can be satisfactorily assessed in fetuses with and without left heart obstructive lesions. We believe that a detailed search for a bicuspid aortic valve should be attempted in all patients referred for a positive family history of congenital heart disease, in general, and of left ventricle outflow tract obstruction or bicuspid aortic valve, in particular. In fact, the presence of an asymptomatic bicuspid aortic valve has been demonstrated to represent an important factor predisposing to the development of bacterial endocarditis and dissecting aortic aneurysm late in adult life. Therefore, an early detection of such an anomaly may contribute to ensure a longer symptom-free lifespan of individuals with the most common cardiac anomaly at birth.