[1] Tufts Univ, Sch Med, Dept Publ Hlth & Community Med, Boston, MA 02111 USA
[2] Vrije Univ Amsterdam, Dept Hlth Sci, Amsterdam, Netherlands
[3] Vrije Univ Amsterdam, EMGO Inst Hlth & Care Res, Amsterdam, Netherlands
[4] Harvard Univ, Boston Childrens Hosp, Dept Neurol, Neuroepidemiol Unit, Boston, MA 02115 USA
[5] Brigham & Womens Hosp, Div Maternal Fetal Med, Boston, MA 02115 USA
[6] Brigham & Womens Hosp, Dept Obstet Gynecol & Reprod Biol, Lab Genital Tract Biol, Boston, MA 02115 USA
[7] Harvard Univ, Sch Med, Boston, MA USA
[8] Boston Med Ctr, Dept Pediat, Div Neurol, Boston, MA USA
[9] Boston Univ, Boston, MA 02215 USA
[10] Wake Forest Univ, Dept Pediat, Winston Salem, NC 27109 USA
[11] Hannover Med Sch, Perinatal Epidemiol Unit, Hannover, Germany