Associate Professor Leader's undergraduate training in medicine was at the University of Cape Town, South Africa.

He completed a Diploma in Anaesthesia (DA) through the Royal College of Surgeons in London in 1974.

His postgraduate training in Obstetrics and Gynaecology was both in London and at Groote Schuur Hospital, Cape Town.

After working as a consultant in Obstetrics and Gynaecology at Groote Schuur Hospital in Cape Town, he was appointed as a Lecturer in Obstetrics and Gynaecology at the Royal Hospital for Women in Sydney in 1981. In 1984, he was promoted to Senior Lecturer, a position he held for over 30 years before being appointed as an Honorary Associate Professor in the School of Women's and Children's Health, UNSW.

He was awarded a Doctor of Medicine by the University of New South Wales in 1988 for his thesis entitled "Fetal Habituation" .

In addition to providing clinical services within the specialty of Obstetrics and Gynaecology at the Royal Hospital for Women, he is an honorary Associate Professor in the School of Women's and Children's Health. He was the School's postgraduate coordinator for many years. He was also responsible for coordinating the curriculum for final year undergraduate medical students.

He has taught Obstetrics and Gynaecology to thousands of undergraduate medical students over the last 30 years. Associate Professor Leader has also been involved in the training of obstetric and gynaecological specialists, many of whom are now working at the Royal Hospital for Women. He is the author of over 50 scientific publications, many book chapters and was the editor of the Obstetric and Gynaecological Handbook. He is actively involved in a number of research programs.

Associate Professor Leader has served as an invited assessor for national medical research organisations in Australia, the United States and Hong Kong and is an invited reviewer for a number of leading international scientific journals.