1. Department of Pediatrics, CHA Medical Center, CHA University School of Medicine, Seoul, Korea.
2. Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Pediatrics, Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
5. Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Department of Pediatrics, Korean Cancer Hospital, Seoul, Korea.
7. Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
8. Department of Pediatrics, Inje University Haeundae Paik Hospital, Busan, Korea.
9. Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
10. Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
11. Department of Pediatrics, Inje University Seoul Paik Hospital, Seoul, Korea.
12. Department of Pediatrics, Korea University College of Medicine, Seoul, Korea.
13. Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
14. Department of Pediatrics, Ajou University School of Medicine, Suwon, Korea.
15. Department of Pediatrics, National Health Insurance Corporation Ilsan Hospital, Goyang, Korea.
16. Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Seoul, Korea.
17. Department of Obstetrics and Gynecology, CHA University School of Medicine, Seoul, Korea.
18. Department of Obstetrics and Gynecology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.