[1] CHA Univ, Sch Med, CHA Med Ctr, Dept Pediat, Seoul, South Korea
[2] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Obstet & Gynecol, Seoul, South Korea
[3] Yonsei Univ, Coll Med, Dept Pediat, Seoul, South Korea
[4] Univ Ulsan, Res Ctr Standardizat Allerg Dis, Childhood Asthma Atopy Ctr, Asan Med Ctr,Coll Med,Dept Pediat, Seoul 138736, South Korea
[5] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Pediat, Seoul, South Korea
[6] Korean Canc Hosp, Dept Pediat, Seoul, South Korea
[7] Seoul Natl Univ, Bundang Hosp, Dept Pediat, Songnam, South Korea
[8] Inje Univ, Haeundae Paik Hosp, Dept Pediat, Pusan, South Korea
[9] Inje Univ, Sanggye Paik Hosp, Dept Pediat, Seoul, South Korea
[10] Sungkyunkwan Univ, Sch Med, Dept Pediat, Kangbuk Samsung Hosp, Seoul, South Korea
[11] Inje Univ, Seoul Paik Hosp, Dept Pediat, Seoul, South Korea
[12] Korea Univ, Coll Med, Dept Pediat, Seoul 136705, South Korea
[13] Hallym Univ, Coll Med, Dept Pediat, Hallym Sacred Heart Hosp, Anyang, South Korea
[14] Ajou Univ, Sch Med, Dept Pediat, Suwon 441749, South Korea
[15] Ilsan Hosp, Natl Hlth Insurance Corp, Dept Pediat, Goyang, South Korea
[16] Yonsei Univ, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[17] CHA Univ, Sch Med, Dept Obstet & Gynecol, Seoul, South Korea
[18] Univ Ulsan, Coll Med, Dept Obstet & Gynecol, Asan Med Ctr, Seoul, South Korea