First-trimester prenatal sonographic diagnosis of ectopia cordis in a twin gestation.

The 11-14-week ultrasound examination allows early pregnancy dating, detection of major anomalies and multiple gestations, and accurate chorionicity determination. We describe a rare case of first-trimester sonographic diagnosis of ectopia cordis in a dichorionic twin pregnancy, illustrating the benefits of early ultrasound in patient counseling and management.