1. Obstetrics and Gynecology and Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Washington School of Medicine, Seattle WA 98195-6460
2. Center for Fetal Medicine, Department of Obstetrics and Gynecology, Karolinska Institute, Huddinge, Sweden
3. Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle WA 98193