1 Division of Pediatric Cardiology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
2 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of California, Los Angeles, CA, USA.
3 Department of Reproductive Medicine, University of California, San Diego, CA, USA.
4 Fetal Diagnostic Centers, Pasadena, Tarzana and Lancaster, CA, USA.
5 Center for Fetal Medicine and Women's Ultrasound, Los Angeles, CA, USA.