1. Department of Obstetrics and Gynecology; Mayo Clinic College of Medicine; Rochester MN USA
2. Women's Health Hospital; Assiut University Hospitals; Assiut Egypt
3. Department of Obstetrics and Gynecology; Baylor College of Medicine and Texas Children's Fetal Center; Houston TX USA
4. Department of Obstetrics; Paulista School of Medicine - Federal University of São Paulo; São Paulo Brazil
5. Prenatal Diagnostic Service, Department of Obstetrics and Gynecology; AUSL Reggio Emilia; Reggio Emilia Italy
6. Centre for Women's and Children's Health, Institute of Metabolism and Systems Research; College of Medical and Dental Sciences, University of Birmingham; Birmingham UK
7. Mayo Clinic Fetal Diagnostic and Therapeutic Center; Mayo Clinic; Rochester, MN USA