Affiliation: | a Department of Obstetrics and Gynecology, Case Western Reserve University, Cleveland, OH b Department of Obstetrics and Gynecology, Ohio State University, Columbus, OH c Biostatistics Center, George Washington University, Washington, DC d Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL e National Institute of Child Health and Human Development, Bethesda, MD f Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT g Department of Obstetrics and Gynecology, University of Chicago, Chicago, IL h Department of Obstetrics and Gynecology, University of Pittsburgh, Pittsburgh, PA i Department of Obstetrics and Gynecology, Wake Forest University, Winston-Salem, NC j Department of Obstetrics and Gynecology, Thomas Jefferson University, Philadelphia, PA k Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI l Department of Obstetrics and Gynecology, University of Cincinnati, Cincinnati, OH m Department of Obstetrics and Gynecology, University of Miami, Miami, FL n Department of Obstetrics and Gynecology, University of Tennessee, Memphis, TN o Department of Obstetrics and Gynecology, University of Texas Health Science Center, San Antonio, TX |