1. Department of Gynecology and Obstetrics, University Hospital of León, 24071 León, Spain
2. Department of Biomedical Sciences, Institute of Biomedicine (IBIOMED), Faculty of Veterinary, University of León, 24071 León, Spain
3. Department of Gynecology and Obstetrics, University Hospital of Oviedo, 33011 Oviedo, Spain
4. Department of Statistics and Operations Research, University of Leon, 24071 León, Spain
5. Department of Sociology, Social Work and Public Health, Faculty of Labour Sciences, University of Huelva, 21071 Huelva, Spain
6. Safety and Health Postgraduate Program, Universidad Espíritu Santo, Guayaquil 092301, Ecuador
7. Health Research Nursing Group (GREIS), Department of Nursing and Physioterapy, University of León, 24071 León, Spain