INS and gestational diabetes: The study will consist of three parts: (1) A systematic review of the literature of the outcomes reported in previous randomised controlled trials of the follow-up at 1 year and beyond of women with GDM treated with insulin and/or oral hypoglycaemic agents; (2) A three-round, online Delphi survey with key stakeholders in order to prioritise these outcomes; and (3) A consensus meeting where the final COS will be decided.