1. Vincent Obstetrics and Gynecology, Massachusetts General Hospital, Boston
2. Department of Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, Massachusetts
3. Department of Obstetrics and Gynecology, University of Washington, Seattle
4. Department of Medicine, University of Minnesota, Minneapolis
5. Department of Epidemiology and Community Health, University of Minnesota, Minneapolis
6. Fred Hutchinson Cancer Research Center, Seattle, Washington
7. Kaiser Permanente Washington Health Research Institute, Seattle
8. Department of Medicine, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota
9. Department of Family Medicine and Public Health, University of California at San Diego, La Jolla
10. Division of Research, Kaiser Permanente of Northern California, Oakland, California