1. Department of Obstetrics and Gynecology, Graduate School of Medicine, Mie University, Tsu, Japan.
2. Department of Obstetrics and Gynecology, St. Marianna University School of Medicine, Kanagawa, Japan.
3. Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan.
4. Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
5. Department of Perinatal and Pediatric Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
6. Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
7. Department of Pediatrics, Graduate School of Medicine, Tohoku University, Sendai, Japan.
8. Department of Obstetrics and Gynecology, Graduate School of Medicine, Tohoku University, Sendai, Japan.
9. Department of Pediatrics, Graduate School of Medicine, Mie University,Tsu, Japan.
10. Department of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto city, Japan.
11. Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto city, Japan.
12. Department of Gynecology and Obstetrics, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan.
13. Division of Hematology/Oncology, Tokyo Metropolitan Children's Medical Center, Fuchu-shi, Japan.
14. Children's Cancer Center, National Center for Child Health and Development, Setagaya-ku, Japan.