1. Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, P.R. China.
2. Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, China.
3. Scientific Center for Family Health and Human Reproduction Problems, Irkutsk, Russia.
4. Irkutsk State Medical Academy for Postgraduate Education, Irkutsk, Russia.
5. Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
6. Pharmaceutical Statistics, Bayer Pharma AG, Beijing, China.
7. Global Clinical Development Women's HealthCare, Bayer AG, Berlin, Germany.