1. Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, Canada.
2. Contraception and Abortion Research Team, Women's Health Research Institute, British Columbia Women's Hospital and Health Centre, Vancouver, Canada.
3. Department of Family Practice, University of British Columbia, Vancouver, Canada.
4. Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom.
5. Department of Family and Community Medicine, University of Toronto, Ontario, Canada.
6. Department of Obstetrics, Gynecology and Reproductive Sciences, University of Manitoba, Manitoba, Canada.
7. Department of Obstetrics, Gynecology and Reproduction, Université Laval, Québec City, Canada.