From the Departments of Pediatrics and Medicine and Epidemiology & Biostatistics, University of California, San Francisco, San Francisco, California; and the Departments of Pediatrics and Obstetrics & Gynecology, Stanford University, Stanford, California.
Supported by National Institutes of Health/National Center for Research Resources/OD UCSF-CTSI Grant No. KL2 RR024130. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Institutes of Health.
Corresponding author: Henry C. Lee, MD, MS, Department of Pediatrics, Division of Neonatology, University of California, San Francisco, 533 Parnassus Avenue, Room U503, San Francisco, CA 94143-0734; e-mail:[email protected].
Financial Disclosure The authors did not report any potential conflicts of interest.