1. Department of Pediatrics, Oakland University William Beaumont School of Medicine and Division of Neonatology, Beaumont Children's Hospital, Royal Oak, Michigan
2. Department of Neonatal and Developmental Medicine, Lucile Salter Packard Children's Hospital, Stanford University, Palo Alto, California
3. Division of General Academic Pediatrics, Department of Pediatrics, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
4. Department of Epidemiology and Biostatistics, Department of Pediatrics, University of California, San Francisco, California
5. Department of Pediatrics and Section of Neonatology, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
6. Division of Newborn Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania