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
2. Department of Obstetrics and Gynecology Wayne State University School of Medicine Detroit Michigan USA
3. Department of Obstetrics and Gynecology University of Michigan Ann Arbor Michigan USA
4. Department of Epidemiology and Biostatistics Michigan State University East Lansing Michigan USA
5. Center for Molecular Medicine and Genetics Wayne State University Detroit Michigan USA
6. Detroit Medical Center Detroit Michigan USA
7. Department of Biochemistry, Microbiology, and Immunology Wayne State University School of Medicine Detroit Michigan USA