1. Department of Genetics and Developmental Biology; University of Connecticut Health Center; Farmington CT USA
2. Prenatal Diagnosis Unit, Institute of Gynecology, Obstetrics and Neonatology, Hospital Clinic, Maternitat Campus; University of Barcelona Medical School; Catalonia Spain
3. Department of Chemical Pathology; The Chinese University of Hong Kong, Prince of Wales Hospital; Hong Kong
4. Department of Obstetrics and Gynecology; Columbia University Medical Center; New York NY USA
5. Department of Obstetrics and Gynecology; University of Pennsylvania; Philadelphia PA USA
6. Department of Human Genetics; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
7. Department of Obstetrics and Gynecology; Albert Einstein College of Medicine; New York NY USA
8. Department of Obstetrics and Gynecology; University of Calgary; Calgary AB Canada
9. Department of Obstetrics and Gynecology, Assaf Harofe Medical Center, Sackler Faculty of Medicine; Tel Aviv University; Tel Aviv Israel
10. Department of Obstetrics and Gynecology; Stanford University School of Medicine; Stanford CA USA
11. Department of Obstetrics and Gynecology; Washington University in St Louis; St Louis MO USA
12. Laboratory for Infectious Diseases and Perinatal Screening; National Institute for Public Health and the Environment (RIVM); Bilthoven The Netherlands
13. Prenatal Screening Unit, Clinical Biochemistry Department; Barking Havering & Redbridge University Hospitals, King George Hospital; Goodmayes UK
14. Genetics Program; North York General Hospital; Toronto ON Canada
15. Department of Mathematics and Statistics; University of Plymouth; Plymouth UK
16. Prenatal Diagnosis Unit, Genetic Institute; Sourasky Medical Center; Tel Aviv Israel