1. Leiden University Medical Center; Department of Obstetrics; Leiden Netherlands
2. Leiden University Medical Center; Department of Pediatrics, Division of Neonatology; J6-S, PO box 9600 Leiden Netherlands 2300
3. Leiden University Medical Center; Immunohematology and Blood Transfusion; Leiden Netherlands
4. Sanquin Diagnostic Services; Immunohematology Diagnostics; Amsterdam Netherlands
5. Mater Mothers' Hospital, Mater Research, The University of Queensland; South Brisbane Australia