1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Center for Women's Reproductive Health, University of Alabama at Birmingham, Birmingham, Alabama
2. Department of Obstetrics and Gynecology, the University of Texas Medical Branch, Galveston, Texas
3. Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina
4. Ochsner Health System, New Orleans, Louisiana
5. Department of Obstetrics and Gynecology, The University of Utah, Salt Lake City, Utah
6. Department of Obstetrics and Gynecology, Intermountain Health-LC, Salt Lake City, Utah
7. Columbia University, New York, New York
8. Mission Hospital, Asheville, North Carolina
9. Department of Obstetrics and Gynecology, The University of Mississippi at Jackson, Jackson, Mississippi, the University of Houston, Houston, Texas
10. Department of Obstetrics and Gynecology, The University of Houston, Houston, Texas