Position statement from the Aneuploidy Screening Committee on behalf of the Board of the International Society for Prenatal Diagnosis.

Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, CT, USA Prenatal Diagnosis Unit, Institute of Gynecology, Obstetrics and Neonatology, Hospital Clinic, Maternitat Campus, University of Barcelona Medical School, Catalonia, Spain Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY, USA Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA, USA Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Department of Obstetrics and Gynecology, Albert Einstein College of Medicine, New York, NY, USA Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB, Canada Department of Obstetrics and Gynecology, Assaf Harofe Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA Department of Obstetrics and Gynecology, Washington University in St Louis, St Louis, MO, USA Laboratory for Infectious Diseases and Perinatal Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands Prenatal Screening Unit, Clinical Biochemistry Department, Barking Havering & Redbridge University Hospitals, King George Hospital, Goodmayes, UK Genetics Program, North York General Hospital, Toronto, ON, Canada Department of Mathematics and Statistics, University of Plymouth, Plymouth, UK Prenatal Diagnosis Unit, Genetic Institute, Sourasky Medical Center, Tel Aviv, Israel *Correspondence to: Peter Benn. E-mail: [email protected] This Statement replaces the January 2011 Statement (Prenatal Diagnosis 2011;31:519–522) and the Rapid Response Statement (Prenatal Diagnosis 2012;32:1–2).