1. Department of Epidemiology, Faculty of Medicine Prince of Songkla University Songkhla Thailand
2. Department of Obstetrics and Gynecology, Faculty of Medicine Prince of Songkla University Songkhla Thailand
3. Department of Pathology, Faculty of Medicine Prince of Songkla University Songkhla Thailand
4. Department of Community Public Health, School of Public Health Walailak University Nakhon Si Thammarat Thailand
5. Obstetrics and Gynecology Division, Naradhiwas Rajanagarindra Hospital Narathiwat Thailand