[1] Wayne State Univ, Hutzel Womens Hosp, Perinatol Res Branch, NICHD,NIH,DHHS, Detroit, MI 48201 USA
[2] NICHD, Perinatol Res Branch, NIH, DHHS, Bethesda, MD USA
[3] Wayne State Univ, Hutzel Hosp, Dept Obstet & Gynecol, Detroit, MI 48201 USA
[4] Wayne State Univ, Ctr Mol Med & Genet, Detroit, MI 48201 USA
[5] Univ Chile, Dept Obstet & Gynecol, Jose Joaquin Aguirre Hosp, Santiago, Chile
[6] Clin Alemana, Maternal Fetal Med Unit, Santiago, Chile
[7] Pontificia Univ Catolica Chile, Sotero del Rio Hosp, Dept Obstet & Gynecol, CEDIP Ctr Perinatal Diag & Res, Santiago, Chile