1. Center of Fetal Medicine, Department of Obstetrics; Copenhagen University Hospital; Rigshospitalet Copenhagen Denmark
2. Faculty of Medicine and Health Sciences; University of Copenhagen; Copenhagen Denmark
3. Section of Biostatistics, Department of Public Health; University of Copenhagen; Copenhagen Denmark
4. Department of Clinical Biochemistry; Copenhagen University Hospital, Herlev and Gentofte Hospital; Copenhagen Denmark
5. Fetal Medicine Unit, Department of Obstetrics and Gynecology; Aarhus University Hospital; Skejby Denmark