1. Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
2. Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Oregon Health & Science University, Portland, Oregon
3. Department of Obstetrics and Gynecology, Intermountain Healthcare, Salt Lake City, Utah
4. Department of Obstetrics and Gynecology, University of Utah Health, Salt Lake City, Utah
5. Clinical Microbiology Laboratory, Los Angeles County-University of Southern California Medical Center, Los Angeles, California