^○Keisuke Oyama¹, Kazunori Nakamoto², Makiko Omori¹, Hiroko Fukasawa¹, Shuji Hirata¹ (1.Department of Obstetrics and Gynecology, University of Yamanashi, Japan, 2.Center for Medical Education and Sciences, Faculty of Medicine, University of Yamanashi, Japan)

^○Sayako Ikeda, Sawako Fujiwara, Yumi Sunohara, Hiroka Akita, Utako Fujii, Miho Sano, Shigehiko Morikawa (Department of Obstetrics and Gynecology, Komaki City Hospital, Aichi, Japan)

^○Takeshi Fukuda, Kenji Imai, Makoto Yamauchi, Mari Kasai, Tomoyuki Ichimura, Tomoyo Yasui, Toshiyuki Sumi (Department of Obstetrics and Gynecology, Osaka City University, Japan)

^○Naoto Yonetani¹, Rie Masaki¹, Yuka Miyatani¹, Ryuji Mitani¹, Hiromi Shiomi², Masahiko Maegawa¹ (1.Department of Obstetrics and Gynecology, Tokushima Prefectural Central Hospital, Tokushima, Japan, 2.Shinkura Ladies Clinic, Japan)

^○Kentaro Kai, Nobutomo Tonai, Tomoko Oishi, Tomonori Yamada, Yoko Aoyagi, Masakazu Nishida, Yasushi Kawano (Department of Obstetrics and Gynecology, Oita University, Oita, Japan)

^○Mamiko Iseki¹, Hiroki Morita¹, Aya Tanabe¹, Mizuho Kurosima¹, Yuri Tomura¹, Moe Tanaka¹, Nobue Kozima¹, Takuya Takahasi², Utaru Tanaka³, Yui Yamasaki⁴ (1.Department of Obstetrics and Gynecology, Konan Medical Center, Japan, 2.Department of Pathology, Konan medical center, Japan, 3.Department of Radiology, Konan medical center, Japan, 4.Department of Obstetrics and gynecology, Kobe university, Japan)

^○Naoyuki Ida, keiichiro nakamura, kyohei irie, kazuhiro okamoto, hirofumi mastuoka, kotaro kubo, Chikako ogawa, hisashi masuyama (Department of Obstetrics & Gynecology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan)

^○Isao Murakami¹, Rena Takahashi¹, Tsuyoki Kugimiya¹, Jyunichi Shiraishi², Hiroshi Yamashita³, Kyoko Tanaka¹ (1.Department of Obstetrics and Gynecology, Toho University Ohashi Medical Center, Japan, 2.Department of Pathology, National Hospital Organization Tokyo Medical Center, Japan, 3.Department of Obstetrics and Gynecology, National Hospital Organization Tokyo Medical Center, Japan)

^○Kazuhiro Nishioka¹, Kotaro Kitani², Kounosuke Yamamoto¹, Yasuhiro Hashiguchi¹, Sachiko Kishimoto¹, Tomoko Wakasa³, Hidekazu Ooi¹ (1.Department of Obstetrics and Gynecology, Kindai Nara Hospital, Nara, Japan, 2.Department of Surgery, Kindai Nara Hospital, Nara, Japan, 3.Department of Pathology, Kindai Nara Hospital, Nara, Japan)

^○Kaori Moriuchi, Yasushi Kotani, Yoshie Yo, Akiko Kanto, Kosuke Murakami, Hisamitsu Takaya, Hidekatsu Nakai, Noriomi Matsumura (Kindai University, Japan)

^○Kuniaki Ota, Mineto Morita, Takafumi Mukai, Masafumi Katakura, Kentaro Nakaoka, Toshimitsu Maemura, Yukiko Katagiri (Department of Obstetrics and Gynecology, Toho University, Japan)

^○Yoko Honda, Mayuko Naka, Yuri Takemura, Rino Matsuo, Hiroki Nakabayashi, Haruka Kawano, Yuka Yamashita, Tetsuro Kondo, Katsufumi Otsuki (Department of Obstetrics and Gynecology, University, Showa, Japan)

^○Kaoru Kawasaki, Kaori Moriuchi, Yasushi kotani, Noriomi Matsumura (Kindai University, Japan)

^○Nobuki Hayashi¹, Aki Maebayashi¹, Saki Kamata¹, Sena Yonekura¹, Yasuji Miyakawa¹, Masaji Nagaishi¹, Kei Kawana² (1.Department of Obstetrics and Gynecology, Nihon University Hospital, Tokyo, Japan, 2.Department of Obstetrics and Gynecology, Nihon University School of Medicine, Tokyo, Japan)

^○Toshiyuki Okumura, Koji Ijichi, Natuko Mizukami, Sumie Kaya, Yuya Makino, Kaori Kishida, Kyoko Oguma, Sumire Ishii, Masaya Takahashi, Motoharu Ono, Takuhiko Ichiyama, Ai Takamizu, Akari Koizumi, Takafumi Ujihira, Shintaro Makino (Department Obstetrics and Gynecology, Juntendo University Urayasu Hospital, Chiba, Japan)

^○Kei Ameda¹, Tomoko Tanaka¹, Takashi Hara¹, Megumi Shibata¹, Shinichi Hoshi¹, Shoichi Watanabe¹, Tsutomu Araki¹, Shigeo Akira² (1.Department of Obstetrics and Gynecology, Araki Memorial Tokyo Riverside Hospital, Tokyo, Japan, 2.Department of Obstetrics and Gynecology, Nippon Medical School Hospital, Tokyo, Japan)

^○Nami Tamura, Keisuke Murakami, Rie Ozaki, Asako Ochiai, Yu Kawasaki, Shinichirou Ikuma, Yukiko Okada, Mari Kitade, Atsuo Itakura (Department of Obstetrics and Gynecology, Juntendo University, Tokyo, Japan)