1. Cambodian Society of Gynecology and Obstetrics, Phnom Penh, Cambodia.
2. Bureau of International Health Cooperation, National Center for Global Health and Medicine, Tokyo, Japan.
3. National Institute of Public Health, Phnom Penh, Cambodia.
4. Department of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, Japan.
5. Department of Obstetrics and Gynecology, Graduate School of Medicine, Osaka University, Osaka, Japan.