1. Department of Obstetrics and Gynecology University of Rochester Medical Center Rochester NY USA
2. Department of Obstetrics and Gynecology Massachusetts General Hospital Boston MA USA
3. Department of Obstetrics and Gynecology University of Pennsylvania Philadelphia, PA, USA
4. David Geffen School of Medicine Department of Obstetrics and Gynecology, University of California Los Angeles CA USA
5. Center for Fetal Medicine and Women's Ultrasound Los Angeles CA USA
6. Department of Obstetrics and Gynecology Columbia University Medical Center New York NY USA
7. Department of Obstetrics and Gynecology and Reproductive Sciences University of California San Francisco San Francisco CA USA
8. Department of Obstetrics and Gynecology Medical College of Wisconsin Milwaukee WI USA
9. Perinatal Quality Foundation Oklahoma City OK USA
10. Tel Aviv University Faculty of Medicine, Ramat Aviv Israel