1. Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina
2. Department of Obstetrics and Gynecology, University of Alabama at Birmingham
3. Department of Obstetrics and Gynecology, Kaiser Permanente San Diego, San Diego, California
4. Department of Obstetrics and Gynecology, University of New Mexico, Albuquerque
5. Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia
6. Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland
7. Department of Obstetrics and Gynecology, Brown University, Providence, Rhode Island
8. Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
9. Department of Urology, Cleveland Clinic, Cleveland, Ohio
10. Social, Statistical and Environmental Sciences, RTI International, Research Triangle Park, North Carolina
11. Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland