1. Department of Paediatrics, Juntendo University Urayasu Hospital, Chiba, Japan
2. Department of Obstetrics and Gynaecology, Juntendo University Urayasu Hospital, Chiba, Japan
3. Department of Respiratory Diseases, Tokyo Metropolitan Children’s Medical Center, Tokyo, Japan
4. Department of Paediatrics, Juntendo University Faculty of Medicine, Tokyo, Japan