1. Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
2. Center for Health Technology and Services Research (CINTESIS@RISE), Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
3. Department of Obstetrics and Gynecology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
4. Department of Obstetrics and Gynecology, Centro Hospitalar Universitário de São João, 4200-319 Porto, Portugal
5. Department of Community Medicine, Information and Health Decision Sciences, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal