1. Université Libre de Bruxelles; School of Public Health; 808, Route de Lennik, CP 592 Brussels Belgium 1070
2. Shanghai Institute of Planned Parenthood Research (SIPPR); Centre for Clinical Research and Training; 2140 Xie Tu Road Shanghai China 200032
3. Ghent University; Center for Reproductive Health; Gent Belgium
4. World Health Organization; Department of Reproductive Health and Research; 20 Via Appia Geneva Switzerland 1211