1. Division of Fetal Medicine, Department of Obstetrics; Leiden University Medical Center; Leiden The Netherlands
2. Division of Fetal Medicine, Department of Obstetrics; CMCO-HUS Strasbourg, Strasbourg; France
3. Division of Medical Statistics; Leiden University Medical Center, Leiden; The Netherlands
4. Division of Neonatology, Department of Pediatrics; Leiden University Medical Center; Leiden The Netherlands