[1] Cleveland Clin, Obstet Gynecol & Womens Hlth Inst, Cleveland, OH 44195 USA
[2] Loyola Univ, Dept Obstet & Gynecol, Stritch Sch Med, Chicago, IL 60611 USA
[3] Loyola Univ, Dept Urol, Stritch Sch Med, Chicago, IL 60611 USA
[4] Univ Alabama Birmingham, Div Gerontol Geriatr & Palliat Care, Birmingham, AL USA
[5] Dept Vet Affairs, Birmingham, AL USA
[6] Univ Alabama Birmingham, Dept Obstet & Gynecol, Birmingham, AL USA
[7] Univ Utah, Med Ctr, Dept Obstet & Gynecol, Salt Lake City, UT 84132 USA
[8] Duke Univ, Med Ctr, Dept Obstet & Gynecol, Durham, NC 27710 USA
[9] Kaiser Permanente So Calif, Dept Obstet & Gynecol, San Diego, CA USA
[10] Univ Calif San Diego Hlth Syst, Dept Reprod Med, San Diego, CA USA
[11] Univ Texas SW Med Ctr Dallas, Dept Obstet & Gynecol, Dallas, TX 75390 USA
[12] Kaiser Permanente So Calif, Dept Obstet & Gynecol, Downey, CA USA
[13] Duquesne Univ, Dept Phys Therapy, Pittsburgh, PA 15219 USA
[14] Univ Michigan, Dept Biostat, Ann Arbor, MI 48109 USA
[15] RTI Int, Social Stat & Environm Sci, Res Triangle Pk, NC USA
[16] Eunice Kennedy Shriver Natl Inst Child Hlth & Hum, Bethesda, MD USA