1. Department of Obstetrics and Gynecology, National Maternal and Child Health Center, Phnom Penh, Cambodia.
2. Bureau of International Health Cooperation, National Center for Global Health and Medicine, Tokyo, Japan.
3. Department of Obstetrics and Gynecology, Khmer-Soviet Friendship Hospital, Phnom Penh, Cambodia.
4. School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.
5. Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
6. Cambodian Society of Gynecology and Obstetrics, Phnom Penh, Cambodia.
7. Department of Obstetrics and Gynecology, Nihon University School of Medicine, Tokyo, Japan.