1. Department of Obstetrics, Maternal‐Fetal Medicine Unit Hospital Universitario Vall d'Hebron, Universitat Autònoma de Barcelona Barcelona Spain
2. Maternal and Child Health and Development Network (SAMID) Instituto de Salud Carlos III Madrid Spain
3. Department of Reproductive Medicine Instituto Bernabeu Alicante Spain
4. Microbiome Lab Hospital Universitario Vall d'Hebron; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD); Department of Medicine, Universitat Autònoma de Barcelona Cerdanyola del Vallès Spain
5. Women and Perinatal Health Research Group Institut d'Investigació Biomèdica de Sant Pau (IIB‐Sant Pau). Hospital Universitari de Sant Pau Barcelona Spain
6. Maternal‐Fetal Medicine Unit, Department of Obstetrics Hospital Universitario Materno‐Infantil de Canarias Las Palmas de Gran Canaria Spain
7. Department of Obstetrics Hospital de Sant Pau Barcelona Spain
8. Department of Obstetrics and Gynecology Hospital Universitari Sant Joan de Reus Reus Spain
9. Department of Obstetrics Hospital Universitario de Torrejón, Universidad Francisco de Vitoria Madrid Spain