1. Department of Obstetrics and Gynecology, Inje University Busan Paik Hospital, Busan, Korea.
2. Paik Institute for Clinical Research, Inje University Busan Paik Hospital, Busan, Korea.
3. Department of General Surgery, Paik Institute for Clinical Research, Inje University Busan Paik Hospital, Busan, Korea.
4. Department of Obstetrics and Gynecology, Kosin University Gospel Hospital, Busan, Korea.
5. Department of Obstetrics and Gynecology, Haeundae Paik Hospital, Busan, Korea.