1. Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
2. The Emmes Company, Rockville, Maryland
3. Northwestern University Feinberg School of Medicine, Chicago, Illinois
4. Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
5. Ochsner Baptist Medical Center, New Orleans, Louisiana
6. Center for Women's Reproductive Health, The University of Alabama at Birmingham, Birmingham, Alabama
7. Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York