Prediction of Outcome of Tricuspid Valve Malformations Diagnosed During Fetal Life

There are conflicting reports on the prenatal validity of echocardiographic indexes used to assess tricuspid valve malformations (TVM) in postnatal life. The aim of this study was to determine which echocardiographic factors are of most prognostic significance in prenatally-diagnosed TVM and to develop a clinically-based prognostic scoring system to better inform prenatal counseling. From a prospective database, 44 fetuses with isolated TVM were identified from 1995 to 2004, inclusive. Prenatal echocardiographic findings were correlated with known outcome in 43. Tricuspid valve dyplasia was diagnosed in 22, Ebstein's anomaly in 21, and unguarded tricuspid valve orifice in 1. There were 19 terminations, 9 intrauterine deaths, 5 neonatal deaths, and 10 survivors >1 month. Survival was 35% at birth and 23% at 1 month, or 63% and 42% respectively on an intention-to-treat basis. There was no significant change to termination or overall survival rates over time, but there was a significant improvement in survival for live-born babies in the second 5 years compared with the first (p = 0.02). Factors significantly associated with increased mortality included increased cardiothoracic ratio (p <0.001), Celermajer index (p <0.001), and right-left ventricular ratio (p = 0.02); reduced/absent pulmonary valve flow (p = 0.02), and retrograde duct flow (p = 0.003). These factors were combined to give a prognostic score (SAS score) with good predictive value. In conclusion, the prenatal echocardiographic factors of most prognostic significance in TVM are similar to those used postnatally. The SAS score is a useful clinical tool that may be used to inform counseling in affected pregnancies.