Objective. The purpose of this series was to determine the sensitivity of ultrasonography in early gestation (UEG) using nuchal translucency (NT) and the 4-chamber view (4CV) in the early diagnosis of congenital heart defects (CHDs). Methods. This was a retrospective chart review of all patients presenting for UEG between 2002 and 2009. At our center, a survey of fetal anatomy is performed at the time of the NT assessment at 11 weeks to 13 weeks 6 days. A second-trimester scan (STS) is done at 20 to 23 weeks and a third-trimester scan at 32 to 35 weeks. Suspected cases of CHDs were evaluated by a pediatric cardiologist. All neonates were examined at birth by a pediatrician, and when clinically indicated, fetal echocardiography was performed. Results. A total of 1370 fetuses were scanned. Congenital heart defects were identified in 8 (0.6%). Nuchal translucency was above the 95th percentile for gestational age (GA) in 6 of 8, and the 4CV was abnormal in 6 of 8. Ultrasonography in early gestation detected 75% fetuses with CHDs, and 25% were detected by an STS. Conclusions. Our study emphasizes the importance of UEG in the detection of CHDs. In this small unselected lowrisk population, UEG detected 75% of CHDs. Nuchal translucency was above the 95th percentile for GA, the 4CV was abnormal, or both in all 8 cases with CHDs. Key words: congenital heart defects; first-trimester scan; 4-chamber view; nuchal translucency; ultrasonography in early gestation. irst-trimester screening, using nuchal translucency (NT), tricuspid regurgitation, and ductus venosus flow, has been shown to be associated with early detection of congenital heart defects (CHDs). 1,2 This, coupled with the improvement in the resolution of today's ultrasound machines, is leading to the advocacy of incorporating routine cardiac evaluation at the time of the first-trimester scan (FTS). [3][4][5][6][7] The value of prenatal detection of CHDs has been shown to improve the outcome of these neonates when they are delivered at tertiary care centers equipped for handling them. 8,9 In addition, first-and early second-trimester detection provides ample time for a full workup: karyotype as well as assessment by pediatric cardiology. If termination of pregnancy were an option, then the earlier the diagnosis, the less the risks to the mother because the risks increase with advancing gestation, bearing in mind the limitations on termination beyond a certain gestational age (GA) in various parts of the world. This is further intensified by the emotional and psychological