1. Fetal Medicine Centre; Royal London Hospital, Barts Health NHS Trust; London UK
2. Fetal Medicine Unit; St George's Healthcare NHS Trust; London UK
3. Clinical Biostatistics Unit; Hospital Ramon y Cajal (IRYCIS); Madrid Spain
4. CIBER Epidemiology and Public Health (CIBERESP); Madrid Spain
5. Women's Health Research Unit, Multidisciplinary Evidence Synthesis Hub (mEsh), Centre for Primary Care and Public Health; Blizard Institute; Barts and The London School of Medicine and Dentistry London UK
6. London School of Medicine and Dentistry; Queen Mary University of London; London UK