[1] Hokkaido University Graduate School of Medicine,Department of Obstetrics and Gynecology
[2] Saitama Medical University,Department of Obstetrics and Gynecology, Center for Maternal, Fetal, and Neonatal Medicine, Saitama Medical Center
[3] Juntendo University Urayasu Hospital,Department of Obstetrics and Gynecology
[4] Aiiku Maternal and Child Health Center,Department of Obstetrics and Gynecology
[5] Aiiku Hospital,Department of Obstetrics and Gynecology
[6] Tokyo Metropolitan Bokutoh Hospital,Department of Obstetrics and Gynecology
[7] Mie University Graduate School of Medicine,Department of Obstetrics and Gynecology
[8] Hamamatsu Medical Center,Department of Obstetrics and Gynecology
[9] Juntendo University Graduate School of Medicine,undefined
[10] The Japan Society of Obstetrical,undefined
[11] Gynecological and Neonatal Hematology,undefined