1. Department of Midwifery, Puerta de Hierro Majadahonda University Hospital, Madrid, Spain.
2. Neonatology and Newborn Nursery Division, Puerta de Hierro Majadahonda University Hospital, Madrid, Spain.
3. Department of Obstetrics, Puerta de Hierro Majadahonda University Hospital, Madrid, Spain.
4. Clinical Biostatistics Unit, Puerta de Hierro Majadahonda University Hospital, Instituto de Investigación Puerta de Hierro (IDIPHIM), Madrid, Spain.
5. Department of Nursing, Autónoma University, Madrid, Spain.
6. Department of Neonatology, Puerta de Hierro Majadahonda University Hospital, Madrid, Spain.
7. Department of Pediatrics, Autónoma University, Madrid, Spain.