Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 7 5 2023 02 12 249 252 Shadi Zamansaraei Assistant professor of Obstetrics and Gynecology Surgery, Isfahan University of Medical Sciences, Isfahan, Iran. Milad Nazari Sabet School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Parvin Bahrami Department of Cardiology, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. 2022 04 17 2022 06 08 The Fontan operation is a palliative procedure for patients with several forms of congenital heart disease unsuitable for biventricular circulation, especially tricuspid valve atresia. In this procedure, the vena cava flow is directed to the pulmonary arteries bypassing the ventricle. Pregnant patients with Fontan surgery in their post-surgical history have more maternal risks. We should counsel patients with saturations <85%, depressed ventricular function, refractory arrhythmia, or protein-losing enteropathy against pregnancy (mWHO; IV). In this study, we review a pregnant case that has successful pregnancy and Fontan palliation and lv systolic heart failure (LVEF: 35%) in her pas t medical history. https://crcp.tums.ac.ir/index.php/crcp/article/view/675