1. Maternal Fetal Medicine; Osaka Medical Center and Research Institute for Maternal and Child Health; Izumi Japan
2. Obstetrics; Tokuyama Central Hospital; Tokuyama Japan
3. Department of Maternal Fetal and Neonatal Medicine; National Center for Child Health and Development; Tokyo Japan
4. Division of Perinatology, Maternal and Perinatal Care Center; Seirei Hamamatsu General Hospital; Hamamatsu Japan