1. RTI International, Research Triangle Park, NC
2. Rollins School of Public Health, Emory University, Atlanta, GA
3. Pregnancy and Perinatology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
4. University of Texas Health Science Center at San Antonio, San Antonio, Texas
5. University of Utah School of Medicine, Salt Lake City, UT
6. Brown University School of Medicine, Providence, RI
7. University of Texas Medical Branch at Galveston, Galveston, TX
8. Emory University School of Medicine, Atlanta, GA
9. Drexel University School of Medicine, Philadelphia, PA, USA