1. Wits Reproductive Health & HIV Institute, University of the Witwatersrand, Johannesburg, South Africa
2. London School of Hygiene & Tropical Medicine, London, UK
3. Centre for Health Policy, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
4. International Centre for Reproductive Health, Department of Obstetrics and Gynaecology, Ghent University, Ghent, Belgium