1 Department of Pediatrics, Kyorin University, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan. Electronic address: kusuda-satoshi@nrnj.org.
2 Department of Newborn Care, The Royal Hospital for Women, School of Women's and Children's Health University of New South Wales, Baker St, Randwick, NSW, 2031, Australia. Electronic address: j.oei@unsw.edu.au.