1. Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital (M.B., W.L., S.M.), Headington, Oxford, OX3 9DU;
2. School of Biological and Molecular Sciences, Oxford Brookes University (N.G.), Oxford OX3 0BP;
3. The Fertility and Endocrinology Center, Lister Hospital (H.A.), London, United Kingdom