1. Department of Obstetrics and Gynecology, Hospital de la Florida, Santiago, Chile
2. Department of Obstetrics and Gynecology, Hospital Padre Hurtado, Santiago, Chile
3. Department of Obstetrics and Gynecology, Faculty of Medicine, Clínica Alemana de Santiago – Universidad del Desarrollo, Santiago, Chile
4. Darent Valley Hospital, Dartford, UK
5. Department of Obstetrics and Gynecology, Hospital Clinico Universidad de Chile, Santiago, Chile