Objective: Our purpose was to assess the prevalence, cause, and clinical significance of fetal tricuspid valve regurgitation in structurally normal hearts during indicated fetal echocardiographic examination.
Study design: The prevalence of fetal tricuspid regurgitation was retrospectively evaluated in a group of 733 singleton fetuses referred for routine fetal echocardiography.
Results: The prevalence of this abnormality was 6.8%. Tricuspid valve regurgitation was most frequent in the group referred for fetal echocardiography to evaluate indomethacin exposure, followed by maternal diabetes. Factors associated with tricuspid valve regurgitation included ductal constriction, abnormal heart rhythm, atrial septal aneurysm, congestive heart failure, pericardial effusion, myocardial hypertrophy, and extracardiac malformations. Fetal tricuspid valve regurgitation was trivial in 80% (nonholosystolic, maximum velocity < 2 m/sec) and was significant in 20% (holosystolic, maximum velocity > 2 m/sec). Neonatal follow-up of tricuspid valve regurgitation was unremarkable.
Conclusions: Fetal tricuspid valve regurgitation with normal heart anatomy was a frequent finding during indicated fetal echocardiographic examination and may indicate abnormal physiologic characteristics (increased preload or afterload, myocardial impairment, or arrhythmia). In the majority of cases (92%) the possible cause may be established. In other cases (8%) there may be "idiopathic" tricuspid valve regurgitation.