A fetus with hypoplastic left heart syndrome and tricuspid stenosis with evolving hydrops fetalis.

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect that results in death if not treated shortly after birth. In approximately 60 to 70% of cases, HLHS can be detected prenatally and generally is well tolerated due to the presence of the foramen ovale and ductus arteriosus, which allow for blood to bypass the left side of the heart but still provide adequate blood flow to the systemic circulation. A rare case of HLHS involving a fetus with tricuspid valve stenosis, abnormal venous Doppler findings, and hydrops is reported.