Affiliations

• ¹ Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL.
• ² Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX.
• ³ Department of Obstetrics and Gynecology, The Ohio State University Medical Center, Columbus, OH.
• ⁴ Department of Obstetrics and Gynecology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA.
• ⁵ Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX.
• ⁶ Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University, New York, NY.
• ⁷ Department of Obstetrics and Gynecology, University of Tennessee Health Science Center, Memphis, TN.
• ⁸ Department of Obstetrics and Gynecology, University of California, Irvine, Irvine, CA.
• ⁹ Department of Obstetrics and Gynecology, Northwestern Perinatal Center, Portland, OR.
• ¹⁰ Department of Obstetrics and Gynecology, Northshore Medical Group, Evanston, IL.
• ¹¹ Department of Obstetrics and Gynecology, University of Texas Medical School at Houston, Houston, TX.
• ¹² Department of Obstetrics and Gynecology, Saint Peter's University Hospital, New Brunswick, NJ.
• ¹³ Department of Obstetrics and Gynecology, Wilford Hall, USAF Medical Center, San Antonio, TX.
• ¹⁴ Department of Obstetrics and Gynecology, University of Cincinnati, Cincinnati, OH.
• ¹⁵ Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK.
• ¹⁶ Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL.