1. Center of Maternal-Fetal, Neonatal and Reproductive Medicine; National Center for Child Health and Development; Tokyo Japan
2. Department of Obstetrics and Gynecology; Kyushu University Hospital, Kyushu University; Fukuoka Japan
3. Department of Fetal-Maternal Medicine; Nagara Medical Center; Gifu Japan
4. Department of Maternal Fetal Medicine; Osaka Medical Center and Research Institute for Maternal and Child Health; Izumi Japan
5. Department of Pediatric Surgery; Osaka Medical Center and Research Institute for Maternal and Child Health; Izumi Japan