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