1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center , Dallas, Texas , USA
2. Parkland Health , Dallas Texas , USA
3. Division of Infectious Diseases and Geographic Medicine, Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas , USA
4. Department of Microbiology and Immunology, Oregon Health and Science University , Portland, Oregon , USA
5. Department of Immunology, University of Texas Southwestern Medical Center , Dallas, Texas , USA