1. Department of Obstetrics & Gynaecology; Faculty of Medicine; Khon Kaen University; Khon Kaen Thailand
2. Department of Biostatistics & Demography; Faculty of Public Health; Khon Kaen University; Khon Kaen Thailand
3. Faculty of Medicine, Dentistry and Health Sciences; School of Population Health; University of Western Australia; Crawley WA Australia
4. UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction; Department of Reproductive Health and Research; World Health Organization; Geneva Switzerland
5. Department of Health Policy; National Center for Child Health and Development; Tokyo Japan