1. Department of Obstetrics and Gynecology; Kyoto Prefectural University of Medicine, Graduate School of Medical Science; Kyoto Japan
2. Department of Obstetrics and Gynecology; Gifu University; Gifu Japan
3. Department of Obstetrics and Gynecology; Kyoto First Red Cross Hospital; Kyoto Japan
4. Department of Obstetrics and Gynecology; Kyoto City Hospital; Kyoto Japan
5. Department of Obstetrics and Gynecology; Hyogo College of Medicine; Nishinomiya Japan
6. Department of Obstetrics and Gynecology; Chibune General Hospital; Osaka Japan
7. Department of Obstetrics and Gynecology; Kuwana City Medical Center; Kuwana Japan
8. Department of Obstetrics and Gynecology; Kansai Rosai Hospital; Amagasaki Japan