1. Departments of Family Medicine and Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia
2. Pregnancy and Perinatology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland
3. Center for Food Safety and Applied Nutrition, Department of Health and Human Services, Food and Drug Administration, College Park, Maryland