[1] Boston Childrens Hosp, Div Newborn Med, 300 Longwood Ave,Enders Res Bldg,Room 961, Boston, MA 02115 USA
[2] Massachusetts Gen Hosp Children, Div Neonatol & Newborn Med, Boston, MA USA
[3] New England Res Inst, Ctr Epidemiol & Stat Res, 9 Galen St, Watertown, MA 02172 USA
[4] Intermt Healthcare, Dept Women & Newborns, Salt Lake City, UT USA
[5] Univ Iowa, Div Neonatol, Iowa City, IA USA
[6] Emory Univ, Dept Pathol, Ctr Transfus & Cellular Therapies, Atlanta, GA 30322 USA
[7] Emory Univ, Dept Pediat, Aflac Canc Ctr & Blood Disorders, Atlanta, GA 30322 USA
[8] Univ Florida, Div Neonatol, Gainesville, FL USA