About the Authors

Nicholas J. Wald

n.j.wald@qmul.ac.uk

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, London, United Kingdom

Jonathan P. Bestwick

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, London, United Kingdom

Competing Interests

Nicholas Wald is a Director of Intema, which holds patents for the Integrated test as follows (Application No; Country; Filing Date; Patent No; Issue/Grant Date): 09/301,621; US; 29.04.99; 6,573,103; 03.06.03 36213/99; Australia; 29.04.99; 763171; 31.10.06 2330538; Canada; 29.04.99; 2330538; 11.09.07 99918188; Europe; 29.04.99;1076824; 14.06.06 139302; Israel; 29.04.99; 139302; 26.10.05. The subject matter in this paper has been submitted as an application for patents. With others he held a patent in connection with the use of uE3 as a second trimester screening marker in prenatal screening for Down syndrome, although this has now expired. He is Director of Logical Medical Systems Ltd, which produces software for the interpretation of Down's syndrome screening tests. There are no further patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Author Contributions

Conceived and designed the experiments: NW. Performed the experiments: NW JB. Analyzed the data: NW JB. Wrote the paper: NW JB.