About the Authors

Daniel B. DiGiulio

Affiliations Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America, Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America

Roberto Romero

Affiliations Perinatology Research Branch, National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, and Detroit, Michigan, United States of America, Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America

Harold P. Amogan

Affiliation Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America

Juan Pedro Kusanovic

Affiliations Perinatology Research Branch, National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, and Detroit, Michigan, United States of America, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, United States of America

Elisabeth M. Bik

Affiliations Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America, Department of Microbiology and Immunology, Stanford University, Stanford, California, United States of America

Francesca Gotsch

Affiliation Perinatology Research Branch, National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, and Detroit, Michigan, United States of America

Chong Jai Kim

Affiliations Perinatology Research Branch, National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, and Detroit, Michigan, United States of America, Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan, United States of America

Offer Erez

Affiliations Perinatology Research Branch, National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, and Detroit, Michigan, United States of America, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, United States of America

Sam Edwin

Affiliation Perinatology Research Branch, National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, and Detroit, Michigan, United States of America

David A. Relman

relman@stanford.edu

Affiliations Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America, Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America, Department of Microbiology and Immunology, Stanford University, Stanford, California, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: DBD RR EMB DAR. Performed the experiments: DBD HPA. Analyzed the data: DBD RR HPA JPK EMB FG CJK OE SE DAR. Contributed reagents/materials/analysis tools: RR DAR. Wrote the paper: DBD RR JPK EMB FG OE SE DAR. Placental pathology diagnosis: CJK. Determination of IL-6 concentrations in amniotic fluid: SE. Collection of data (demographic and clinical): OE FG JPK RR.