1. School of Clinical Medicine; Department of Obstetrics and Gynaecology; University of the Witwatersrand; Johannesburg South Africa
2. School of Public Health; University of the Witwatersrand; Johannesburg South Africa
3. SACEMA (DST/NRF Centre of Excellence in Epidemiological Modelling and Analysis); Stellenbosch University; Stellenbosch South Africa
4. Wits Reproductive Health and HIV Institute; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
5. International Centre for Reproductive Health; Department of Obstetrics and Gynaecology; University of Ghent; Ghent Belgium
6. Anova Health Institute; Johannesburg South Africa
7. School of Public Health and Family Medicine; University of Cape Town; Cape Town South Africa