1. Departments of Blood Transfusion and Transplantation Immunology, Obstetrics and Gynecology, and Epidemiology and Biostatistics, University Medical Center Nijmegen, The Netherlands; Department of Obstetrics and Gynecology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
2. Departments of Blood Transfusion and Transplantation Immunology, Obstetrics and Gynecology, and Epidemiology and Biostatistics, University Medical Center Nijmegen, The Netherlands; Department of Obstetrics and Gynecology, Erasmus University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.