1. Fertility and Infertility Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20817, USA
2. Department of Obstetrics and Gynecology, Pennsylvania State University, Hershey, PA 16802, USA
3. Department of Obstetrics and Gynecology, Augusta University, Augusta, GA 30912, USA
4. Department of Biostatistics, Yale University School of Public Health, New Haven, CT 06520, USA
5. Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI 48109, USA
6. Department of Neurology, University of Michigan, Ann Arbor, MI 48109, United States
7. Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA 19104, USA
8. Department of Obstetrics and Gynecology, University of Oklahoma College of Medicine, Oklahoma City, OK 73104, USA
9. Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Denver, CO 80204, USA