Aortic regurgitation associated with critical aortic stenosis in a fetus.

Aortic regurgitation in association with aortic stenosis is rare in the fetus. Findings have shown that severe aortic regurgitation is worsened by the increase in systemic vascular resistance after birth, resulting in low cardiac output, hypoxemia, and neonatal death. This report describes a unique case of aortic regurgitation with aortic stenosis, severe mitral regurgitation, retrograde flow in the aortic arch, and an enormous left atrium with a restrictive foramen ovale in a fetus. In this case, aortic regurgitation was diminished immediately after birth, indicating that spontaneous improvement in aortic regurgitation after birth should be taken into account when the final prognosis is predicted.