1. Department of Obstetrics and Gynecology, Graduate School of Medicine, Mie University, 2-174 Edo-bashi, Tsu, Mie 514-8507, Japan
2. Department of Obstetrics and Gynecology, Mie University Hospital, 2-174 Edo-bashi, Tsu, Mie 514-8507, Japan
3. Center of Advanced Reproductive Medicine, Mie University Hospital, 2-174 Edo-bashi, Tsu, Mie 514-8507, Japan
4. Faculty of Education, Mie University, 1577 Kurima-Machiya-cho, Tsu, Mie 514-8507, Japan
5. Department of Obstetrics and Gynecology, IVF Osaka Clinic, 1-1-14 Nagatahigashi, Higashiosaka, Osaka 577-0012, Japan
6. Department of Obstetrics and Gynecology, Kawato Ladies Clinic, 1-16-11 Betsumei, Yokkaichi, Mie 510-0007, Japan
7. Department of Obstetrics and Gynecology, Minoura Ladies Clinic, 3-9-17 Isoyama, Suzuka, Mie 510-0256, Japan
8. Department of Obstetrics and Gynecology, Saiseikai Matsusaka General Hospital, 15-6 asahimachiichiku, Matsusaka, Mie 515-8557, Japan