1 Division of Obstetrics and Gynecology, The University of Western Australia, Crawley, Australia; Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan. Electronic address: haruo.usuda@uwa.edu.au.
2 Division of Obstetrics and Gynecology, The University of Western Australia, Crawley, Australia; Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan.
3 Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan.
4 Division of Obstetrics and Gynecology, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia; Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan.