["Sociology of Health & Illness, EarlyView. ", "\nAbstract\nIn this article we explore the recent enactment of evidence‐based medicine (EBM) in the field of fertility care. We aim to contribute to the medical sociology literature through an analysis of how evidence is produced, interpreted and institutionalised in a relatively new medical field such as in vitro fertilisation (IVF), characterised by high uncertainty due to limited knowledge and high levels of commercialisation. Drawing on extensive ethnographic research conducted in England, this article explores the challenges IVF professionals encounter in producing credible data on the effectiveness of additional treatments, offering novel insights on the tensions between commercialisation and standardisation in the enactment of EBM. Extant medical sociology and Science and Technology Studies literature has shown the hidden professional work required to enact randomised control trials in practice. Our analysis shows that this hidden work is not enough when there is a broader lack of standardisation in both clinical and research practices, as producing ‘good quality’ evidence requires high levels of standardisation of knowledge production.\n"]