[1] Case Western Reserve Univ, Metrohlth Med Ctr, Dept Gynecol & Obstet, Cleveland, OH 44106 USA
[2] NICHD, Div Epidemiol Stat & Prevent Res, NIH, Bethesda, MD USA
[3] Univ Miami, Dept Obstet Gynecol, MFM Div, Miami, FL USA
[4] Cedars Sinai Med Ctr, Los Angeles, CA 90048 USA
[5] Univ Illinois, Chicago, IL USA
[6] Univ Texas Houston, Hlth Sci Ctr, Houston, TX USA
[7] NICHD, NIH, Bethesda, MD USA
[8] Emmes Corp, Rockville, MD USA
[9] Tufts Univ, Baystate Med Ctr, Medford, MA 02155 USA
[10] Univ Utah, Salt Lake City, UT USA
[11] Christiana Hosp, Newark, DE USA
[12] Maimonides Hosp, Brooklyn, NY 11219 USA
[13] Indiana Univ, Indianapolis, IN 46204 USA
[14] Georgetown Univ Hosp, Washington, DC 20007 USA
[15] Childrens Hosp & Med Ctr, Akron, OH USA
[16] Intermt Hlth, Salt Lake City, UT USA
[17] Medstar Hlth, Washington, DC USA