1. Department of Obstetrics and Fetal Medicine; Leiden University Medical Center; Leiden The Netherlands
2. Department of Medical Statistics; Leiden University Medical Center; Leiden The Netherlands
3. Department of Pediatric Cardiology; Leiden University Medical Center; Leiden The Netherlands
4. Department of Obstetrics; AMC University Hospital; Amsterdam The Netherlands
5. Department of Obstetrics; VU Medical Center; Amsterdam The Netherlands
6. Department of Pediatric Cardiology; AMC University Hospital; Amsterdam The Netherlands