[1] Yonsei Univ, Coll Med, Dept Obstet & Gynecol, Severance Hosp, Seoul, South Korea
[2] Yonsei Univ, Coll Med, Dept Orthopaed Surg, Severance Hosp, Seoul, South Korea
[3] Yonsei Univ, Coll Med, Dept Biostat Collaborat, Seoul, South Korea
[4] Yonsei Univ, Coll Med, Dept Obstet & Gynecol, Gangnam Severance Hosp, Seoul, South Korea
[5] Yonsei Univ, Coll Med, Inst Womens Life Med Sci, Seoul, South Korea