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