Roberto Romero1. 1. Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland, and Detroit, Michigan, USA; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan, USA; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan, USA; Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, USA; Detroit Medical Center, Detroit, Michigan, USA; Department of Obstetrics and Gynecology, Florida International University, Miami, Florida, USA. Electronic address: rr.ajoged@gmail.com.