[1] IMIM Hosp Mar, Ctr Res Environm Epidemiol, Municipal Inst Med Res, CREAL, E-08003 Barcelona, Spain
[2] Autonomous Univ Barcelona, Dept Farmacol Toxicol & Therapeut, Barcelona, Spain
[3] CIBERESP, Barcelona, Spain
[4] SFHMC, Dept Obstet & Gynecol, Hartford, CT USA
[5] UConn Med Sch, Farmington, CT USA
[6] Univ Crete, Sch Med, Iraklion, Greece
[7] Aarhus Univ Hosp, Dept Clin Epidemiol, Aarhus, Denmark
[8] Boston Univ, Dept Epidemiol, Boston, MA 02215 USA
[9] Univ Aarhus, Inst Publ Hlth, Aarhus, Denmark
[10] Univ Calif Los Angeles, Sch Publ Hlth, Dept Epidemiol, Los Angeles, CA 90024 USA