About the Authors

Jonathan Paul Bestwick

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing

j.p.bestwick@qmul.ac.uk

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London Charterhouse Square, London, United Kingdom

Nicholas John Wald

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London Charterhouse Square, London, United Kingdom

Competing Interests

Nicholas J. Wald is director of Logical Medical Systems, which produces software for the interpretation of prenatal screening tests.This does not alter our adherence to PLOS ONE policies on sharing data and materials. The other authors declare no conflict of interest.