1. Department of Obstetrics and Gynecology, Texas Children’s Hospital, Baylor College of Medicine, Houston, TX, USA;
2. Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD and Detroit, MI, USA;
3. Division of Maternal Fetal Medicine, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada;
4. Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA;
5. Department of Epidemiology & Biostatistics, Michigan State University, East Lansing, MI, USA;
6. Department of Molecular Obstetrics and Genetics, Wayne State University, Detroit, MI, USA