1. Department of Maternal-Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia (ICGON); Hospital Clinic; Barcelona Spain
2. Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); University of Barcelona; Barcelona Spain
3. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER); Barcelona Spain
4. Department of Obstetrics and Gynecology; Hadassah-Hebrew University Medical Center; Mt. Scopus Jerusalem Israel
5. Department of Obstetrics and Gynecology; University Hospitals Leuven; Leuven Belgium
6. Department of Obstetrics, Gynecology & Reproductive Sciences; University of Maryland School of Medicine; Baltimore MD 21201-1559 USA
7. Frauenklinik und Poliklinik; Technische Universität München; Munich Germany