1. Department of Obstetrics and Gynecology, Hospital Universitario La Paz, 28046 Madrid, Spain
2. Instituto de Investigación IdiPaz, Hospital Universitario La Paz, 28029 Madrid, Spain
3. Department of Obstetrics and Gynaecology, Faculty of Medicine, Universidad Autónoma de Madrid, 28029 Madrid, Spain
4. Department of Physiology, Faculty of Medicine, Universidad Autónoma de Madrid, 28029 Madrid, Spain
5. Instituto Universitario de Estudios de la Mujer (IUEM), Universidad Autónoma de Madrid, 28049 Madrid, Spain