1. Department of Obstetrics and GynecologyStanford University School of MedicineStanfordCaliforniaUSA
2. Department of OtolaryngologyStanford University School of MedicineStanfordCaliforniaUSA
3. Department of Obstetrics and GynecologySt. Mariana UniversityKawasakiJapan
4. Department of Obstetrics and GynecologyAkita University Graduate School of MedicineAkitaJapan