1. Primary Care Midwife OSI Barakaldo-Sestao Osakidetza Basque Health Service, Bizkaia, Spain
2. Biocruces-Bizkaia Health Research Institute, Bizkaia, Spain
3. School of Nursing, University of the Basque Country, Bizkaia, Spain
4. Midwifery Training Unit of Basque Country, Bilbao, Spain
5. Osakidetza Basque Health Service-OSI General Management, Bizkaia, Spain
6. The ema-Q Group: Multidisciplinary Group of Midwives, Medical Professionals, Psychologists and Researchers of Osakidetza Basque Health Service and University of Basque Country, Bizkaia, Spain
7. Methodological and Statistical Consulting, Bizkaia, Spain