1. Department of Maternal Fetal Medicine; Osaka Prefectural Hospital Organization, Osaka Medical Center and Research Institute for Maternal and Child Health; Izumi Japan
2. Department of Obstetrics and Gynecology; Kagoshima City Hospital; Kagoshima Japan
3. Maternal and Perinatal Care Center; Seirei Hamamatsu General Hospital; Hamamatsu Japan
4. Department of Fetal-Maternal Medicine; Nagara Medical Center; Gifu Japan
5. Department of Obstetrics and Gynecology; Hiroshima City Hospital; Hiroshima Japan
6. Division of Perinatology, Feto-Maternal Center; Hyogo Prefectural Kobe Children's Hospital; Kobe Japan
7. Department of Maternal-Fetal and Neonatal Medicine; National Center for Child Health and Development; Tokyo Japan