[1] NICHD, Perinatol Res Branch, NIH, Detroit, MI 48201 USA
[2] NICHD, Perinatol Res Branch, NIH, Bethesda, MD USA
[3] Vet Affairs Palo Alto Hlth Care Syst, Palo Alto, CA USA
[4] Stanford Univ, Sch Med, Dept Med, Stanford, CA 94305 USA
[5] Wayne State Univ, Sch Med, Ctr Mol Med & Genet, Detroit, MI 48201 USA
[6] Wayne State Univ, Sch Med, Dept Obstet & Gynecol, Hutzel Womens Hosp,Detroit Med Ctr, Detroit, MI 48201 USA
[7] Hosp Dr Sotero del Rio, CEDIP Ctr Perinatal Diag & Res, Dept Obstet & Gynecol, Santiago, Chile
[8] Pontificia Univ Catolica Chile, Dept Obstet & Gynecol, Santiago, Chile
[9] Wayne State Univ, Sch Med, Dept Pathol, Detroit, MI 48201 USA
[10] Stanford Univ, Dept Microbiol & Immunol, Stanford, CA 94305 USA