Note: Funding Information: During the last 4 year period BCJM Fauser has received salary/fees or grant support from the following organisations (in alphabetic order); Abbott, Controversies in Obstetrics & Gynecology (COGI), Dutch Heart Foundation (Hartstichting), Dutch Medical Research Counsel (ZonMW), Ferring, International Federations of Fertility Societies (IFFS), London Women's Clinic (LWC), Menogenix, Myovant, OvaScience, Pantharei Bioscience, PregLem/Gedeon Richter, Reproductive Biomedicine Online (RBMO), Teva/Theramex, University Medical Center Utrecht (UMCU), and the World Health Organisation (WHO). Copyright: Copyright 2019 Elsevier B.V., All rights reserved.