[1] Johns Hopkins Univ, Sch Med, Div Gen Pediat, Dept Pediat, Mason F Lord Ctr Tower 4200 Eastern Ave, Baltimore, MD 21218 USA
[2] Univ Maryland, Reprod Hlth Educ Family Med RHEDI, Dept Family & Community Med, Sch Med, Baltimore, MD USA
[3] Prisma Hlth, Div Maternal Fetal Med, Dept Obstet & Gynecol, Greenville, NC USA
[4] Univ South Carolina, Sch Med, Greenville, SC USA
[5] Indiana Univ Sch Med, Dept Pediat, Childrens Hlth Serv Res, Indiana, PA USA