1 Department of Genetics and Genome Sciences, 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 Genetics Program, North York General Hospital, Toronto, ON, Canada.
9 Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB, Canada.
10 Department of Obstetrics and Gynecology, Assaf Harofe Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
11 Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA.
12 Department of Obstetrics and Gynecology, University of South Florida, Tampa, FL, USA.
13 Laboratory for Infectious Diseases and Perinatal Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
14 Prenatal Screening Unit, Clinical Biochemistry Department, Barking Havering & Redbridge University Hospitals, King George Hospital, Goodmayes, UK.
15 Department of Statistics, University of Exeter, Exeter, UK.
16 Prenatal Diagnosis Unit, Genetic Institute, Sourasky Medical Center, Tel Aviv, Israel.