^○Hiromitsu Shirasawa, Yukiyo Kumazawa, Wataru Sato, Kazue Togashi, Ayaka Fujishima, Yukihiro Terada (Department of Obstetrics and Gynecology, Graduate School of Medicine, Akita University, Akita, Japan)

^○Shin Takenaka¹, Yuki Koike¹, Shun Odajima¹, Koji Matsumoto², Hiroshi Tanabe¹ (1.Department of gynecology, National cancer center hospital east, Chiba, Japan, 2.Department of obstetrics and gynecology, Showa university hospital, Tokyo, Japan)

^○Hisanori Komatsu, Yimiko Tsukui, Hisanobu Sadakata, Issei Kagami (Kiryu kosei general hospital, Japan)

^○Masaaki Tamura, Toshihiko Toki (Fukui Maternity Clinic, Gunma, Japan)