The National Institutes of Health, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Center for Advancing Translational Sciences (NCATS) provided grant support for the Neonatal Research Network’s Generic Database Study through cooperative agreements. While NICHD staff had input into the study design, conduct, analysis, and manuscript drafting, the comments and views of the authors do not necessarily represent the views of NICHD, the National Institutes of Health, the Department of Health and Human Services, or the U.S. Government. Participating NRN sites collected data and transmitted it to RTI International, the data coordinating center (DCC) for the network, which stored, managed, and analyzed the data for this study. On behalf of the NRN, RTI International had full access to all of the data in the study and with the NRN Center Principal Investigators, takes responsibility for the integrity of the data and accuracy of the data analysis. We are indebted to our medical and nursing colleagues and the infants and their parents who agreed to take part in this study. The following investigators, in addition to those listed as authors, participated in this study: NRN Steering Committee Chair: Richard A. Polin, MD, Division of Neonatology, College of Physicians and Surgeons, Columbia University, (2011-present). Alpert Medical School of Brown University and Women & Infants Hospital of Rhode Island (UG1 HD27904) – Abbot R. Laptook, MD; Martin Keszler, MD; Angelita M. Hensman, PhD RNC-NIC; Elisa Vieira, BSN RN; Lucille St. Pierre, BS. Case Western Reserve University, Rainbow Babies & Children’s Hospital (UG1 HD21364) – Anna Maria Hibbs, MD MSCE; Michele C. Walsh, MD MS; Nancy S. Newman, RN; Sarah Smucney, RN; Arlene Zadell, RN. Cincinnati Children’s Hospital Medical Center, University of Cincinnati Medical Center, and Good Samaritan Hospital (UG1 HD27853, UL1 TR77) – Brenda B. Poindexter, MD MS; Kurt Schibler, MD; Cathy Grisby, BSN CCRC; Kristin Kirker, CRCII; Sandra Wuertz, RN BSN, Juanita Dudley, RN BSN; Traci Beiersdorfer, RN BSN; Julia Thompson, BSN. Duke University School of Medicine, University Hospital, University of North Carolina, Duke Regional Hospital, and WakeMed Health and Hospitals (UG1 HD40492, UL1 TR1117, UL1 TR1111) – Ronald N. Goldberg, MD; Joanne Finkle, RN JD; Kimberley A. Fisher, PhD FNP-BC IBCLC; Matthew M. Laughon, MD MPH; Gennie Bose, RN; Cindy Clark, RN; Stephen D. Kicklighter, MD; Donna White, BSN RN-BC. Emory University, Children’s Healthcare of Atlanta, Grady Memorial Hospital, and Emory University Hospital Midtown (UG1 HD27851, UL1 TR454) – David P. Carlton, MD; Yvonne Loggins, RN; Judith Laursen, RN; Colleen Mackie, BS RT; Diane I. Bottcher, RN MSN. Eunice Kennedy Shriver National Institute of Child Health and Human Development – Andrew A. Bremer, MD PhD; Rosemary D. Higgins, MD; Stephanie Wilson Archer, MA. McGovern Medical School at The University of Texas Health Science Center at Houston, Children’s Memorial Hermann Hospital, and Memorial Hermann Southwest Hospital (U10 HD21373, UG1 HD87229) – Jon E. Tyson, MD MPH; Amir M. Khan, MD; Barbara J. Stoll, MD; Gabriela Dominguez, BSN; Elizabeth Eason, MD; Donna J. Hall, RN; Apoorva Mahatme, MPH; Karen Martin, RN; Ilse Reyna, IMG, Emily K. Stephens, BSN RNC-NIC, Jaleesa Wade, RN BSN; Michelle White, BSN. Nationwide Children’s Hospital, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Center for Perinatal Research, The Ohio State University College of Medicine, The Ohio State University Wexner Medical Center, and Riverside Methodist Hospital (UG1 HD68278) – Leif D. Nelin, MD; Sudarshan R. Jadcherla, MD; Jonathan L. Slaughter, MD MPH; Patricia Luzader, RN; Jacqueline McCool; Kyrstin Warnimont, BS; Jessica Purnell, BS CCRC; Kristi Small, BS; Melanie Stein, RRT BBA; Rox Ann Sullivan, RN BSN; Laura Marzac, MD; Hallie Baugher, BS, MSN; Eli Zettler, BS; Bethany Miller, RN BSN; Demi R. Beckford, MHS; Brittany DeSantis BS; Rachel Reedy RN. RTI International (U10 HD36790) – Marie G. Gantz, PhD; Carla M. Bann, PhD; Kristin M. Zaterka-Baxter, RN BSN CCRP; Jenna Gabrio, MPH CCRP; David Leblond, BS; Jeanette O’Donnell Auman, BS. Stanford University and Lucile Packard Children’s Hospital (UG1 HD27880, UL1 TR93) – Krisa P. Van Meurs, MD; David K. Stevenson, MD; Valerie Y. Chock, MD MS Epi; M. Bethany Ball, BSc CCRC; Barbara P. Recine, MA; Elizabeth N. Reichert, MA CCRC. University of Alabama at Birmingham Health System and Children’s Hospital of Alabama (UG1 HD34216) – Monica V. Collins, RN BSN MaEd; Shirley S. Cosby, RN BSN. University of Iowa and Sanford Health (UG1 HD53109, M01 RR59, UL1 TR442) – Tarah T. Colaizy, MD MPH; Heidi M. Harmon, MD MS; Michelle L. Baack, MD; Laurie A. Hogden, MD; Karen J. Johnson, RN BSN; Mendi L. Schmelzel, MSN RN; Jacky R. Walker, RN; Claire A. Goeke, RN; Sarah E. Faruqui, MSN RN; Brenda J. Coulter, RN; Bailey M. Schrimper, RN MSN; Syndney S. Jellison, BS; Chelsey Elenkiwich, NNP APRN CNP; Megan M. Henning, RN; Megan Broadbent, RN BSN; Sarah Van Muyden, RN BSN. University of New Mexico Health Sciences Center (UG1 HD53089, UL1 TR41) – Janell Fuller, MD; Robin K. Ohls, MD; Sandra Sundquist Beauman, MSN RNC-NIC; Conra Backstrom Lacy, RN; Mary Hanson, RN BSN; Elizabeth Kuan, RN BSN. University of Pennsylvania, Hospital of the University of Pennsylvania, Pennsylvania Hospital, and Children’s Hospital of Philadelphia (UG1 HD68244) – Sara B. DeMauro, MD MSCE; Eric C. Eichenwald, MD; Soraya Abbasi, MD; Christine Catts, CRNP; Aasma S. Chaudhary, BS RRT; Megan A. Dhawan, MSN CRNP; Sarvin Ghavam, MD; Toni Mancini, RN BSN CCRC; Karen M. Puopolo, MD PhD; Jonathan Snyder, RN BSN. University of Rochester Medical Center, Golisano Children’s Hospital, and the University at Buffalo John R. Oishei Children’s Hospital of Buffalo (UG1 HD68263, UL1 TR42) – Ronnie Guillet, MD PhD; Anne Marie Reynolds, MD MPH; Satyan Lakshminrusimha, MD; Michael G. Sacilowski, MAT CCRC; Mary Rowan, RN; Rosemary Jensen; Rachel Jones; Alison Kent, BMBS FRACP MD; Diane Prinzing, AAS; Ann Marie Scorsone, MS CCRC; Kyle Binion, BS; Stephanie Guilford, BS; Constance Orme; Premini Sabaratnam, MPH; Daisy Rochez, BS MHA; Emily Li, BA; Jennifer Donato, BS. University of Texas Southwestern Medical Center, Parkland Health & Hospital System, and Children’s Medical Center Dallas (UG1 HD40689) – Luc P. Brion, MD; Joanne Duran, RN; Frances Eubanks, RN BSN; Michelle Harrod, RN; Pollieanna Sepulvida, RN; Diana M. Vasil, MSN RNC-NIC BSN. University of Utah Medical Center, Intermountain Medical Center, McKay-Dee Hospital, Utah Valley Hospital, and Primary Children’s Medical Center (UG1 HD87226, UL1 TR105) – Bradley A. Yoder, MD; Mariana Baserga, MD MSCI; Stephen D. Minton, MD; Mark J. Sheffield, MD; Carrie A. Rau, RN BSN CCRC; Susan Christensen, RNC BSN; Kathleen Coleman, RN; Jennifer O. Elmont, RN BSN; Barbara L. Francom, RN BSN; Jamie Jordan, RN BSN; Manndi C. Loertscher, BS CCRP; Trisha Marchant, RNC; Earl Maxson, RN CCRN; Kandace McGrath, BS; Hena G. Mickelsen, BA; D. Melody Parry, RN BSN; Katherine Tice, RN BSN; Kimberlee Weaver-Lewis, RN MS; Kathryn D. Woodbury, RN BSN.