[1] Brigham & Womens Hosp, Div Maternal Fetal Med, Boston, MA 02115 USA
[2] Beth Israel Deaconess Med Ctr, Dept Pathol, Boston, MA 02215 USA
[3] Tufts Floating Hosp Children, Div Newborn Med, Boston, MA USA
[4] Univ N Carolina, Chapel Hill, NC USA
[5] Brigham & Womens Hosp, Channing Lab, Boston, MA 02115 USA
[6] Bay State Med Ctr, Dept Obstet & Gynecol, Springfield, MA USA
[7] Wake Forest Univ, Baptist Med Ctr, Dept Maternal Fetal Med, Winston Salem, NC 27109 USA
[8] Univ Massachusetts, Mem Med Ctr, Dept Obstet & Gynecol, Worcester, MA 01605 USA
[9] Childrens Hosp, Neuroepidemiol Unit, Boston, MA 02115 USA