[1] Univ Utah Hlth, Dept Obstet & Gynecol, Div Maternal Fetal Med, Salt Lake City, UT 84132 USA
[2] Univ Utah, Dept Internal Med, Program Addict Res Clin Care Knowledge & Advocacy, Div Epidemiol,Sch Med, Salt Lake City, UT 84112 USA
[3] Univ Utah, Sch Med, Dept Pediat, Salt Lake City, UT USA
[4] Ctr Dis Control & Prevent, Atlanta, GA USA
[5] CDC Fdn, Atlanta, GA USA