1. Epidemiology Unit, Hebrew University Braun School of Public Health, P.O. Box 12272, Jerusalem 91120, Israel
2. Department of Human Genetics, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
3. Department of Medicine and Epidemiology, University of Washington, Seattle, WA 98101, USA
4. Obstetric and Gynecology Department, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel