Prof William Ledger is Emeritus Professor, and was previously Head of Discipline of Obstetrics and Gynaecology at the University of New South Wales and Director of Reproductive Medicine at the Royal Hospital for Women, Sydney. He is also a fertility specialist at City Fertility in Sydney. He is immediate past Chair of the RANZCOG Research Assessment Committee, a former member of the NHMRC Working Party reviewing national guidelines on ethics and ART, and chair of the MBS Working Party on costs of ART. His research interests include in vitro fertilisation, assisted reproduction, reproductive ageing, endometriosis, premature ovarian failure, polycystic ovary syndrome, onco-fertility, and the health economics of infertility.