^○Hongxin Wang, Shigenori Hayashi, Kenta Masuda, Yusuke Kobayashi, Hiroshi Nishio, Masaru Nakamura, Wataru Yamagami, Daisuke Aoki (Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan)

^○Kyoko Furumura, Yasushi Sasaki, Honami Teranishi, Kumiko Inada (Department of Obstetrics and Gynecology, Tonami General Hospital, Toyama, Japan)

^○Naoto Sato¹, Tadashi Watanabe¹, Hiroki Kurosawa¹, Hiromi Himuro², Yuma Muraoka³, Toru Nakanishi³, Yoh Watanabe³ (1.Tohoku Medical and Pharmaceutical University Wakabayashi Hospital, Japan, 2.Sendai Red Cross hospital, Japan, 3.Tohoku Medical and Pharmaceutical University Hospital, Japan)

^○Haruhiko Shimizu, Hiroharu Kobayashi, Yumi Shimizu, Misa Kobayashi, Takashi Suzuki, Satoshi Shiojima, Satoru Nakayama, Hiroshi Adachi (Department of Gynecology and Obstetrics Seirei Hamamatsu General Hospital, Shizuoka, Japan)

^○Yuki Sakai, Keiji Morikawa, Keiichi Ohishi, Karen Iwama, Naoko Tanaka, Yoshiaki Tsukizawa, Rinko Kubo, Maiko Ueda, Yosuke Katayama, Shoko Tamada, Masae Yorimitsu, Junichi Kodama (Hiroshima City Hiroshima Citizens Hospital, Japan)

^○Naho Sasai, Mamiko Ota, Hanako Sato, Yoko Kashima, Kiko Yamamoto, Kaori Moriuchi, Chiho Miyagawa, Masato Aoki, Yoshie Yo, Kousuke Murakami, toshimitsu Takaya, Yasushi Kotani, Hidekatsu Nakai, Noriomi Matsumura (Department of Obstetrics and Gynecology, Kindai University, Osaka, Japan)

^○Kaori Kuroda¹, Kaisuke Yamamoto², Miki Takehara¹, Misaki Ogawa¹, Yuei Tetsubayashi¹, Eri Katayama¹, Yuko Okajima¹ (1.Department of Obstetric and Gynecology, National Organization Chiba Medical Center, Japan, 2.Department of Surgery, National Organization Chiba Medical Center, Japan)