1. Department of Family Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
2. Department of Obstetrics and Gynecology, Section of Reproductive Endocrine, Infertility & Genetics, Medical College of Georgia, Augusta University, Augusta, GA, USA
3. Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
4. Department of Obstetrics and Gynecology, University of Chicago, Chicago, IL, USA