1. Knoxville, Tennessee
2. Departments of Obstetrics, Gynecology and Reproductive Sciences and Biochemistry and Molecular Biology, University of Maryland School of Medicine, College Park, Maryland
3. Department of Pregnancy and Perinatology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
4. University of Maryland School of Medicine, College Park, Maryland