Professor Simpson is based at Evelina London Children’s Hospital where he leads the paediatric echocardiography service. He has published over 300 papers in the field. Prof. Simpson is a co-author of the BCCA fetal cardiology standards 2021 and American Society of Echocardiography guidelines on fetal echocardiography (2023). Professor Simpson was President of the British Congenital Cardiac Association between 2019 and 2021