1. Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, GA, USA
2. Fertility and Infertility Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA
3. Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
4. Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
5. Department of Obstetrics and Gynecology, Pennsylvania State University, Hershey, PA, USA
6. Department of Obstetrics and Gynecology, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
7. Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, NC, USA
8. Department of Obstetrics, Gynecology & Reproductive Sciences, University of California San Francisco, San Francisco, CA, USA
9. Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
10. Upstate University Hospital, Syracuse, NY, USA
11. Department of Obstetrics and Gynecology, University of Colorado Denver, Denver, CO, USA