Lawrence D Platt1, Richard A Barth2, Denise Pugash3. 1. Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Center for Fetal Medicine and Women's Ultrasound, Los Angeles, CA, USA. 2. Stanford University School of Medicine, Lucile Packard Children's Hospital at Stanford, Stanford, CA, USA. 3. 1T48 Ultrasound, BC Women's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.