1 Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, Biomedical Research Bldg. II/III, Perelman School of Medicine, University of Pennsylvania, 1351 421 Curie Blvd., Philadelphia, PA 19104-6160; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Electronic address: kristin.gerson@pennmedicine.upenn.edu.
2 Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, Biomedical Research Bldg. II/III, Perelman School of Medicine, University of Pennsylvania, 1351 421 Curie Blvd., Philadelphia, PA 19104-6160; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
3 Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; Children's Hospital of Philadelphia, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.