1. Department of Obstetrics and Gynecology University of Utah Health Sciences Salt Lake City Utah USA
2. Department of Obstetrics and Gynecology Intermountain Health Care Murray Utah USA
3. RTI International Research Triangle Park North Carolina USA
4. Department of Obstetrics and Gynecology University of Virginia Charlottesville Virginia USA
5. Department of Obstetrics and Gynecology University of Texas Medical Branch at Galveston Galveston Texas USA
6. Department of Obstetrics and Gynecology Columbia University New York New York USA
7. Department of Pediatrics McGovern Medical School at University of Texas Health Science Center at Houston Houston Texas USA
8. Department of Epidemiology Rollins School of Public Health Emory University Atlanta Georgia USA
9. Department of Women's Health University of Texas Health Science Center at Austin Austin Texas USA
10. Department of Obstetrics and Gynecology University of Texas Health Science Center at San Antonio San Antonio Texas USA
11. Division of Perinatal Pathology Brown University School of Medicine Providence Rhode Island USA
12. Department of Obstetrics and Gynecology Yale School of Medicine New Haven Connecticut USA