1. Department of Obstetrics and Gynecology and University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
2. Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
3. Center for Women's Health Research, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
4. Veterans Administration Eastern Colorado Health Care System, Denver, Colorado, USA.