1 Department of Obstetrics and Gynecology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO. Electronic address: [email protected].
2 Department of Obstetrics and Gynecology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO.
3 Department of Women's Health, Dell Medical School, The University of Texas at Austin, Austin, TX.