We describe the obstetric anesthetic management of a patient with complex congenital heart anomaly consisting of transposed great arteries, double inlet left ventricle and subpulmonic stenosis. Successful management of a patient with Fontan physiology mandates a thorough understanding of the hemodynamic consequences of this procedure and the alterations during pregnancy. The major considerations are related to the fact that the systemic venous return reaches the pulmonary vasculature without the augmentation of a functioning ventricle.