1. Department of Obstetrics and Gynecology Universidad Pontificia Bolivariana, Medellin Colombia
2. Department of Obstetrics and Gynecology Clinica Universidad de Navarra Pamplona Spain
3. Department of Obstetrics Gynecology, and Reproduction, Hospital Universitario Dexeus Barcelona Spain
4. Department of Obstetrics and Gynecology University of Cagliari, Policlinico Universitario Duilio Casula Cagliari Italy
5. Biostatistics and Epidemiology Unit, Department of Obstetrics Gynecology, and Reproduction, Hospital Universitario Dexeus Barcelona Spain