1 Department of Obstetrics and Gynecology, Sanggye Paik Hospital, Inje University School of Medicine, Seoul, South Korea.
2 Department of Obstetrics and Gynecology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, South Korea.
3 Department of Obstetrics and Gynecology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, South Korea. Electronic address: lsj671121@gmail.com.