A patient who had undergone Pott's procedure and a right Blalock-Taussig shunt in childhood for complex cyanotic congenital heart disease with a single ventricle presented with a planned pregnancy at age 22. Although asymptomatic prior to pregnancy, she experienced functional deterioration from the first trimester and had preterm labor with a footling breech presentation at 29 weeks following prelabor rupture of the membranes. A normal, 900-g female infant was delivered by cesarean section. Despite delivery the patient continued to experience progressive functional deterioration and returned to her prepregnancy cardiac status only after a Fontan operation, performed 14 months postpartum.