Dr. O’Brien is a consultant neonatologist at the Neonatal Unit, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford. She leads the Neonatal Transitional Care Service and the Neonatal Neurodevelopmental Follow-Up Programme. She qualified from The London Hospital Medical College, London in 1993 and trained as a paediatrician at The Royal London Hospital and Queen Elizabeth Hospital for Children. She held the post of Research Fellow at University College London investigating the mechanisms and prevention of perinatal brain injury and the long-term effects of prematurity.
She completed her training as a Neonatologist at University College London Hospitals NHS Foundation Trust and Barts and The London NHS Trust and was appointed as a consultant at the John Radcliffe Hospital in 2009.