Affiliation: | a Departments of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL b Departments of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX c Departments of Obstetrics and Gynecology, The Ohio State University Medical Center, Columbus, OH d Departments of Obstetrics and Gynecology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA e Departments of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX f Departments of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University, New York, NY g Departments of Obstetrics and Gynecology, University of Tennessee Health Science Center, Memphis, TN h Departments of Obstetrics and Gynecology, University of California, Irvine, Irvine, CA i Departments of Obstetrics and Gynecology, Northwestern Perinatal Center, Portland, OR j Departments of Obstetrics and Gynecology, Northshore Medical Group, Evanston, IL k Departments of Obstetrics and Gynecology, University of Texas Medical School at Houston, Houston, TX l Departments of Obstetrics and Gynecology, Saint Peter's University Hospital, New Brunswick, NJ m Departments of Obstetrics and Gynecology, Wilford Hall, USAF Medical Center, San Antonio, TX n Departments of Obstetrics and Gynecology, University of Cincinnati, Cincinnati, OH o Departments of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK p Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL |