Nielsen KK, et al. – The focus of this study is to investigate factors that might impact timely initiation and completion of the gestational diabetes mellitus (GDM) screening and diagnosis process in a sample of urban and rural women in Tamil Nadu (TN). Minimising and aligning complex stepwise processes of prenatal care and GDM screening delivery and attention to the factors impacting it are imperative for further improving and expanding GDM screening and related services, not only in Tamil Nadu but in other similar low and middle–income settings. This study stresses the significance of guidelines and diagnostic criteria which are simple and feasible on the ground.