[1] Univ Iowa, Coll Publ Hlth, Dept Epidemiol & Biostat, S416 CPHB,145 N Riverside Dr, Iowa City, IA 52242 USA
[2] Univ Iowa, Coll Publ Hlth, Interdisciplinary Program Toxicol, S416 CPHB,145 N Riverside Dr, Iowa City, IA 52242 USA
[3] Univ Iowa, Dept Epidemiol, Iowa City, IA USA
[4] Univ Arizona, Dept Pediat, Tucson, AZ USA
[5] Univ Iowa, Dept Biostat, Iowa City, IA USA
[6] Univ Iowa, Dept Pediat, Iowa City, IA USA
[7] Univ Iowa, Dept Neurol, Iowa City, IA USA
[8] Univ Rochester, Med Ctr, Dept Neurol, Rochester, NY USA
[9] Univ Rochester, Med Ctr, Dept Pediat, Rochester, NY USA
[10] Univ Colorado, Dept Phys Med & Rehabil, Aurora, CO USA
[11] Univ Colorado, Childrens Hosp Colorado, Aurora, CO USA
[12] Colorado Sch Publ Hlth, Dept Epidemiol, Aurora, CO USA
[13] Ctr Dis Control & Prevent, Natl Ctr Birth Defects & Dev Disabil, Atlanta, GA USA
[14] Gen Dynam Informat Technol, Coralville, IA USA