Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 7 3 2022 11 02 109 116 Nasir Hematian Department of Perinatology and Fetal Cardiology, Yas Hospital, Tehran University of Medical Sciences, Tehran, Iran. Shirin Torabi Perinatologist, Fetal-Maternal Research Center, Tehran, Iran. Sedigheh Hantoushzadeh Department Perinatology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Maasoumeh Saleh Department Fetal-Maternal Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Mahboubeh Saleh Fasa University of Medical Sciences, Fars, Iran. 2021 05 11 2021 08 09 CCTGA, also known as levo- or L-loop transposition (L-TGA), double discordance, or ventricular inversion, is a rare cardiovascular anomaly with inversion of the ventricles and great arteries. In this anomaly, the right atrium communicates with the morpho- logic left ventricle, which gives rise to the pulmonary artery, while the left atrium communicates with the morphologic right ventricle, which gives rise to the aorta. Thus, atrioventricular and ventriculoarterial discordance (double discordance) exist, and although the blood flows in the normal direction, it passes through the wrong ventricular chambers. It is a unique conotruncal anomaly, in which the four-chamber view is abnormal. It may be associated with other heart disorders. In most fetuses, TGA remains undiagnosed before birth. The diagnosis of TGA can be made by care- fully and appropriately evaluating the anatomic locations of cardiac chambers and the connections between the atria, ventricles, and great arteries with high-resolution ultrasound. Patients with isolated CTGA generally present later in life with signs and symptoms related to either arrhythmias or heart failure. TGA is rarely associated with chromosomal abnormality and amniocentesis is usually not undertaken. We report a case of CTGA detected at 18 week’s gestation on screening ultrasound.  https://crcp.tums.ac.ir/index.php/crcp/article/view/538