Botros Rizk, MD, MA, FRCOG, FRCS, HCLD, FACOG, FACS Medical Director, California Elite Fertility, Pasadena, California, USA and Shanghai, China; President, Middle East Fertility Society; and formerly Professor and Head, Reproductive Endocrinology & Infertility, Department of Obstetrics & Gynecology, University of South Alabama, Mobile, Alabama, USA Yakoub Khalaf, MB BCh, MSc, MD, FRCOG, MFFP Professor of Reproductive Medicine and Surgery at Guy's and St Thomas' Hospital and King's College London, and Head of Fertility Service and Director of the Assisted Conception Unit and Centre for Pre-Implantation Genetic Diagnosis at Guy's and St Thomas’ Hospital, London, UK