1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama
2. Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina
3. Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas
4. Department of Obstetrics and Gynecology, Ochsner Health System, New Orleans, Louisiana
5. Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah
6. Department of Obstetrics and Gynecology, Intermountain Health Care, Salt Lake City, Utah
7. Department of Obstetrics and Gynecology, Columbia University, New York, New York
8. Department of Obstetrics and Gynecology, Mission Hospital, Asheville, North Carolina
9. Department of Obstetrics and Gynecology, University of Mississippi, Jackson, Mississippi
10. Department of Obstetrics and Gynecology, University of Texas Health Sciences Center, Houston, Texas
11. Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
12. Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama