1. Department of Obstetrics University Hospital Zurich University of Zurich Schmelzbergstrasse 12 8091 Zurich Switzerland
2. Department of Health Sciences and Technology ETH Zurich Universitätstrasse 2 8092 Zurich Switzerland
3. Functional Genomics Center University of Zurich and ETH Zurich Wintherturerstrasse 190 8057 Zurich Switzerland
4. SIB Swiss Institute of Bioinformatics Quartier Sorge – Batiment Amphipole 1015 Lausanne Switzerland
5. Department of Obstetrics University of Zurich Schmelzbergstrasse 12 8091 Zurich Switzerland
6. The Zurich Center for Fetal Diagnosis and Therapy University Hospital Zurich Frauenklinikstrasse 10 8091 Zurich Switzerland
7. Gene Expression Laboratory Salk Institute for Biological Studies 10010 N Torrey Pines Road La Jolla 92037 USA