A Diagnostic Dilemma: Transposition of the Great Arteries.

Transposition of the great arteries (TGA) remains one of the most common and severe underdiagnosed congenital cardiac anomalies in the prenatal period. Unfortunately, despite advances in prenatal ultrasound screening, the detection rate of major congenital heart defects (CHDs) remains low. We present the case of a preterm male infant delivered limp with generalized cyanosis and in respiratory distress at 36 weeks gestation with postnatal echocardiography (ECHO) depicting dextro-TGA (d-TGA). Maternal prenatal targeted fetal anomaly ultrasonography at 18 weeks gestation showed abnormal right ventricle and right ventricular outflow tract. Subsequent two-time repeat fetal ECHO showed ventricular septal defect. This case represents how challenging and unrecognized critical CHDs can be. Furthermore, it highlights the need for clinicians to have a high index of suspicion when newborns present with clinical manifestations of critical CHDs and manage it accordingly to avoid severe complications.