[1] Ctr Dis Control & Prevent, Natl Ctr Birth Defects & Dev Disabil, Atlanta, GA USA
[2] Univ Missouri, Sch Med, Kansas City, MO 64108 USA
[3] Univ Colorado, Sch Med, Anschutz Med Campus, Aurora, CO USA
[4] Univ Wyoming, Inst Disabil, Laramie, WY 82071 USA
[5] Univ N Carolina, Dept Epidemiol, Chapel Hill, NC 27515 USA
[6] Univ N Carolina, Ctr Hlth Serv Res, Chapel Hill, NC 27515 USA
[7] Drexel Univ, Coll Nursing & Hlth Profess, Philadelphia, PA 19104 USA
[8] Childrens Hosp Philadelphia, Ctr Autism Res, Philadelphia, PA 19104 USA