1. Department of Obstetrics and Gynecology, Sanggye Paik Hospital, Inje University School of Medicine, Seoul, Korea.
2. Department of Pathology, Sanggye Paik Hospital, Inje University School of Medicine, Seoul, Korea.
3. Department of Obstetrics and Gynecology, Ilsan Paik Hospital, Inje University School of Medicine, Goyang, Korea.