1. GEM School, Barcelona, Spain
2. Center of Primary Health Care Vilassar de Mar, Barcelona, Spain
3. Fetal Medicine Research Center, BCNatal. Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Déu), Institut Clínic de Ginecologia, Obstetrícia I Neonatologia, Universitat de Barcelona, Barcelona, Spain
4. Clinical Research Branch, National Institute of Perinatology, Mexico City, Mexico