Dr. Eichenwald graduated from Harvard Medical School in 1980 and received his training in pediatrics at Boston Children's Hospital. After residency, he received training in Neonatal-Perinatal Medicine in the Joint Program in Neonatology, based at Boston Children's, Brigham and Women’s and the Beth Israel Hospitals. He joined the faculty at Harvard Medical School in 1990, and was a staff neonatologist and Associate Director of the NICU at the Brigham and Women's. He remained on the faculty at Harvard until 2006, when he became the Medical Director of the Newborn Center at Texas Children's Hospital and Associate Professor of Pediatrics at Baylor College of Medicine in Houston. He joined the faculty of the University of Texas and Children’s Memorial Hermann Hospital in 2010, where he was the David R. Park Professor of Pediatric Medicine, Chair of the Department of Pediatrics, Division Director of Neonatal/Perinatal Medicine and Physician-in-Chief at Children’s Memorial Herman Hospital. In 2016, he relocated to the Children’s Hospital of Philadelphia, where he is Chief of the Division of Neonatology, and the Thomas Frederick McNair Scott Endowed Chair, Professor of Pediatrics at the Perelman School of Medicine, University of Pennsylvania. His research interests include clinical trials, resource utilization in neonatal intensive care, inter-NICU variation in management and quality improvement in neonatology, with a particular interest in research in strategies to prevent bronchopulmonary dysplasia, and respiratory control disorders. He is Alternate PI for the Penn site for the NICHD Neonatal Research Network, and co-PI for an NICHD funded RO1 entitled Intermittent Hypoxia and Caffeine Infants Born Preterm. He is author or co-author of over 100 manuscripts and book chapters, as well as co-editor of the Manual of Neonatal Care, now in its 9^th edition.

He is currently a member of the Society for Pediatric Research, the American Pediatric Society, and completed his term as Chair of the Sub-Board for Neonatal-Perinatal Medicine of the American Board of Pediatrics, and is currently a member of the Board of Directors of the ABP, and Chair of the  American Academy of Pediatrics Committee on Fetus and Newborn. He also is an Associate Editor of the Archives of Diseases in Children – Fetal and Neonatal Edition.